The Android Cookbook site at http://androidcookbook.com/, a community for longer-than-snippet code examples with explanations, is having a contest for developer contributors. Prizes include an O'Reilly OSCon "super pass" and a JAXConf 2011 full pass. The former is for total contributions and the latter randomly chosen from those with a minimum level of contribution. There's also cash or O'Reilly books to be had!

http://androidcookbook.com/Rewards.seam