JKRowling.com

The Room of Requirement is probably the coolest thing on Jo's official site. Whenever it opens, it releases something that is usually important.

1. June 28th - July 7th, 2004
Revealed the title of the sixth Harry Potter book:
Harry Potter and the Half-Blood Prince.
**How to Open: Have to click the bricks behind the wall in a certain order.
Visual Demonstration here.

2. August 16 - August 26, 2004
Revealed a passage from Half-Blood Prince:
"He looked rather like an old lion. There were streaks of grey in his mane of tawny hair and his bushy eyebrows; he had keen yellowish eyes behind a pair of wire-rimmed spectacles and a certain rangy, loping grace even though he walked with a slight limp."
**How to Open: Have to open the door and keep clicking in the darkness at the horizontal area below the doorknob and through to the other side of the door. Next you have to play darts and hit the darts at 7, then 1, then 3. Once the darts are in the right order, the board moves aside and you have to put in 6 numbers that were revealed by Peeves on the Extra Stuff page- 302723. Once inside there is a little piece of paper.
Visual Demonstration here.

3. October 31 - November 15, 2004
Revealed chapter titles from Harry Potter and the Half-Blood Prince:
Chapter 2. Spinners End
Chapter 6. Draco's Detour
Chapter 14. Felix Felicis
**How to Open: You can't open the door at first. Wait until Peeves comes through and a bunch of keys will appear. Randomly select keys until one works. Pull the desk drawer open to get the information. Pull out the magnifying glass and place it over the paper on the left side of the desk. You had to answer a riddle, whose answer was "chapters". Then grab the pages on the folder to get the chapter titles.
Visual Demonstration here.

4. December 20th - December 26th, 2004
Revealed a message from Jo:
"I know you all expected this to happen on Christmas day, but I was sure that those of you who celebrate Christmas have better things to on the day itself do than to fight your way into my study, whereas those of you who DON'T celebrate Christmas would definitely prefer not to wait until the twenty fifth so... 'Harry Potter and the Half-Blood Prince' is COMPLETED and has been delivered to my English language publishers, who hope to announce the publication date within 24 hours. Although I have joked about HP&THBP racing my third baby into the world, I have in fact had all the time I needed to tinker with the manuscript to my satisfaction and I am as happy as I have ever been with the end result. I only hope you feel that it was worth the wait when you finally read it! Wishing everybody a wonderful holiday and a happy and peaceful 2005, With love from, JK Rowling."
**How to Open: Click on the door at the end of the hall in the mirror. That closes the mirror door and opens the room of requirement. There is a series of riddles by clicking the Christmas presents, whose answers are (the order changes) Half, Prince, Corned Beef, Blood, Bristol, and Otter. After this click on the middle Christmas card, which opens to reveal Jo's note.
Visual Demonstration here.

5. March 31, 2006 - April 4, 2006
Revealed the WOMBAT Quiz Grade 1.
**How to Open: Click and drag the rock sitting behind the plant over to the mirror. The mirror will shatter and behind it will be two shelves with two keys. Pick the key on the second shelf and place it over the keyhole on the door. After this, click on the note on the shelf which will say you must repair the mirror. Type reparo into the keyboard. Finally, close the door at the end of the hall in the mirror, which will open the Room of Requirement. Once the door is opened, click the tassel on the hat on the desk and move it so it faces up (as in 12:00). The hat will move and the test will come.
Visual Demonstration here.

6. September 29, 2006 - October 4, 2006
Revealed the WOMBAT Quiz Grade 2.
**How to Open: Open the door to the ROR. Do the following things in order: Click on the candle in the upper left side to light the room, click on the quill and place it in the ink, click on the Wombat Revision Book (the open text book), and click on the 4 leaf clover on the bottom left. Drag the key from the desk over to the drawer, which will open. Then click on the hourglass to start the test.
Visual Demonstration here.

7. December 21st - December 28th, 2006
Revealed the title of the 7th Harry Potter book:
Harry Potter and the Deathly Hallows
**How to Open: Click on the empty doorway at the end of the hall in the mirror, making a Christmas tree appear. Click on the door to the ROR in the middle of the top panel of the door. Then go back to the mirror and click on the ceiling, making garland appear Next click either spider web, making them disappear. Click on the chimes in the window, one of which will turn into a key. Pick up the key and place it in the lock in the door. The door will open. Click on the present, which opens and reveals a game of hangman. Play hangman to reveal the title of the book (Deathly Hallows).
Visual Demonstration here.

8. June 13 - June 18, 2007
Revealed the WOMBAT Quiz Grade 3
**How to Open: Click on the fly, making it turn into a key. Drag the key to the keyhole, which will open the door. Drag the circle onto the stick, positioning it toward the bottom of the rod. Once they are placed together they will sparkle. Line up the triangle so the point is facing upward and is lined up with the stick and circle (the deathly hallows sign). Once you have it right, it will sparkle and float toward the top of the desk. Click on the test.
Visual Demonstration here.

9. July 21, 2007 - October 31, 2007
Revealed a letter from Jo:
Acknowledgements:
   Within hours you will know what happens to Harry, Ron, Hermione and the rest in their final adventure. All the secrets I have been carrying around for so long will be yours, too, and those who guessed correctly will be vindicated, and those who guessed wrongly will not, I hope, be too disappointed! As for me, I feel a heady mixture of excitement, nerves and relief. 'Deathly Hallows' remains my favourite of the series, even after several re-reads; I cannot wait to share it with the readers who have stuck with me through six previous books.
   There is only one thing left to do: acknowledgements! Here are the people who have joined me at various stages of the seventeen year journey I have taken with Harry, who (if you laid their brains end to end) could tell a story much stranger than fiction, of how weird and wonderful the world of Harry Potter became as it expanded way beyond all of our wildest dreams.
   I am, firstly, deeply indebted to my agent, Christopher Little, who has been with me from the beginning and who took a chance on an unknown author whom he sweetly advised not to give up the day job, before working tirelessly to make sure that I never needed to teach French irregular verbs again. I bless the day his name caught my eye in the Writers' and Artists' Year Book; thank God he wasn't christened Vernon. Everyone at his (now considerably expanded) agency deserves my deepest thanks, but in particular Emma Schlesinger, who has become an irreplaceable walking encyclopedia of Potterania, and Neil Blair, who has fought so many battles on Harry's and my behalf, and will, hopefully, get his weekends back now.
My eternal gratitude goes to Barry Cunningham, the editor at Bloomsbury Children's books who accepted Philosopher's Stone for publication, but who did not remain at the company long enough to garner all the plaudits that were rightfully his. I had been turned down by a fairly long list of publishers before Barry discerned some merit in Harry; he is a great editor and I will never forget his patience with a writer who was simultaneously struggling to be a teacher and a single mother.
   Barry was succeeded by Emma Matthewson, who has been my editor and friend for the subsequent six Harrys, whose arbitration I have awaited with bated breath every time I delivered a manuscript, and without whose calmness, honesty and sound judgment I would have been lost. The editing of 'Deathly Hallows' was, in particular, hugely emotional for me, and I cannot think of anyone I would rather have shared it with.
   Everyone at Bloomsbury Children's Books has been fantastic to me and worked so hard for Harry, but Rosamund de la Hey and Sarah Odenina were with me from the start and have been staunch friends throughout. Nigel Newton, Chief Executive of Bloomsbury, has been hugely supportive from the very beginning, long before Harry began to sell in vast numbers, because his children were fans of the books; he has been a constant source of enthusiasm and generosity.
   A turning point in my life was the day I spoke to Arthur Levine for the first time. He was the American editor who had just out-bid three other publishers for the first Harry book. I felt terrified as I picked up the telephone to speak to him; the first thing he said was, 'are you terrified?' I think I loved him from that moment. He, too, has become a real friend and confidant, and the memories I have of seeing San Francisco with Arthur on my first American tour are among my happiest of the whole Potter experience.
   The other person at Scholastic whom I must thank is the preternaturally efficient and completely lovely Kris Moran, who has shepherded me through two American tours, and sundry other press events, and whom I adore for her loyalty, her ability to locate coffee in an apparently moisture-free environment and her corner-of-the-mouth-while-opening-books-for-signing quips.
   I also want to thank booksellers everywhere, but particularly in the UK, because they were crucial to Harry's initial success, which was built, not on clever marketing, but on word-of-mouth recommendations by the highly knowledgeable people who staff our bookshops. Harry has become hard work for booksellers in later years, with embargoes and crowds making the whole business much more fraught, and much less intimate, than it used to be (though many still throw themselves into the spirit of midnight openings); I am deeply grateful.
   Harry Potter is now published in 64 different languages. I am constantly mindful of the fact that so many people are involved in the production of the books across the globe, from China to Canada and most places in between. The arrival of foreign editions is always a real thrill, and I am so grateful to all the people involved, some of whom I have met, but most of whom I have not. I would like to send a little cyber-wave and my warmest thanks to Christine, Yuko, Allan, all the Klauses, Pedro and Sigrid. To list everybody would take up twelve pages, so please forgive me...
   Dotti Irving, Mark Hutchinson, Rebecca Salt and Nicky Stonehill at Colman Getty PR have made my life so much easier it makes me wince to remember how it was BCG. Bizarre Potter press stories will fade out of our lives now, and we'll probably miss them once they're gone...
   Here in my office at home are Christine and Angela, who have dealt expertly and sensitively with my Harry-mail for years, making sure I see the letters I ought to, bringing calm where once there was chaos. I am so glad I found both of them, and that they are still hanging in there.
   It is hard to know what to say about my indefatigable, invaluable, indispensable PA, Fiddy, whose job has swollen beyond recognition since I first had lunch with her and told her it would probably fill an afternoon a week. She has stood valiantly between me and a tidal wave of demands for years now, enabling me to write books and look after my children, and barely a day goes by when I don't thank God I have her.
   And so to my family. For a long time, my sister Di was the only one who really saw what it was like at the eye of the storm, and on at least one occasion she picked me up, dusted me down, and talked me back to sanity. She understood that, for all the incredible benefits Harry brought me, there came a time when the pressure and the attention I had not sought became a little overwhelming, and she was the one who saw me through that period, and enabled me to find some perspective.
   No writer ever had a better spouse than my husband. I still cannot believe how lucky I am to have married Neil; I don't think writers are supposed to be this happy. His support has made the writing of the sixth and seventh books, in particular, a complete joy.
   As for my children, my two youngest do not really know what Harry Potter is all about yet. Looking forward to sharing the books with them when they are old enough keeps me from feeling too sad at having finished.
   The very last person to be thanked is the most important person of all, the one to whom I owe the greatest debt of gratitude. I wrote the final draft of the first three chapters of 'Philosopher's Stone' while pregnant with my eldest daughter, Jessica. She has never known what it is like to live without Harry Potter; even before he was published, he was a presence in our house as I typed away frantically in the evenings or broke off conversations with her to scribble on bits of paper. Jessica has never once complained about the attention I devoted to her fictional brother, never reproached me for the fact that Harry Potter has sometimes been a bane rather than a boon in her life. It has not always been easy to be J K Rowling's daughter, yet if I had decided to stop before the seventh book it would have been Jessica's disappointment that I would have feared the most. The fact that 'Deathly Hallows' will sit beside Jessica's bed until it becomes dog-eared and falls apart means more to me than anything else, more than the huge print run, more than all the publicity in the world. So thank you, Decca. (And tidy your room. It's disgusting. Mum X)
Visual Demonstration here.

10. October 31, 2007 - present
Time Turner Appeared
Jo placed a time turner on the site. You can now flip to any date that the door was last opened and see what was inside!