JavaRanch is giving away free books to developers. Here's how it works: every week they invite authors of interesting books to visit, answer questions, and share their knowledge. All you have to do to win is participate in the discussion. On Friday, they comb the forums for qualifying messages and randomly select four winners. The publisher will then send each winner a free copy of the book! The odds of winning are pretty good given the limited number of participants, so see the site for details.