About 1,700 lucky fans in Britain and Ireland will win a chance to have Rowling sign a copy of Harry Potter and the Deathly Hallows. The event will take place at the Natural History Museum on July 21, the day the book is released.

The first 500 randomly selected winners will also be invited to attend the midnight reading. Timed tickets will be issued for the subsequent book signing, which is expected to last until dawn. All the winners will receive a free copy of the book.

Seven U.S. residents can enter to win round-trip tickets to London and hotel accommodations to participate in the reading. Entries to the free contest are available online at the Web sites of publishing houses Scholastic Inc. and Bloomsbury, who are sponsoring the event.