Among her fans, the mania surrounding the release of each novel in J.K. Rowlings series is cranked up this time to a pitch of near-unendurable anticipation: not merely because this is the sagas finale, but since Rowling cannily constructed book number six to confound us with tons of backstory and drive us wild with loose ends and unanswered questions. Most every bookstore in town is throwing some kind of party to celebrate the arrival of Harry Potter and the Deathly Hallows, with trivia and costume contests, door prizes and refreshments. Parkplace Books (348 Parkplace Center, Kirkland) also offers a Story Slam contest; Santoros Books (7216 Greenwood Ave. N., www.santorosbooks.com) will whet your appetite with a reading of the final chapter from book six. All four of the University Bookstore branches (www.bookstore.washington.edu) will feature live music from bands like The Parselmouths and Alas Earwax. Some stores are going philanthropic: Secret Garden Books (2214 N.W. Market St., www.secretgardenbooks.com) will make a book donation equal to 20 percent of the price of each copy sold to a book-related charity, while at Third Place Books (17171 Bothell Way, Lake Forest Park), you can buy an extra copy for kids at Childrens Hospital and Third Place will donate a copy to match it. Speaking of good works: A friend in the book biz told me, after the 2005 release of the sixth Potter, that despite the unprecedented demand, large book dealers were barely making anything, since to get people in the door they were practically selling copies at cost, while smaller dealers, who could hardly afford such deep discounts but who had to stay competitive, were suffering. Factor in the cost of these parties, and some of them were actually losing money on Potter. So how about this: when you gather tonight to buy your copy, why not pick up something else while youre there. Show some love and make it worthwhile for the stores which help you celebrate.