Android Developer Challenge
Cool apps that surprise and delight mobile users—built by developers like you—are a huge part of the Android vision. To support you in your efforts, Google launched the Android Developer Challenge, which will provide awards for great mobile apps built on the Android platform.
For each of the 10 categories:10 More Puzzle Websites to Sharpen Your Programming Skills | Coderholic
Google's Android Developer Challenge: providing awards for great mobile apps built on the Android platformTough Guy Challenge 2009 - The Big Picture - Boston.com
photo essay of tough guy challenge