Google Code Jam is a coding competition in which professional and student programmers are asked to solve complex algorithmic challenges in a limited amount of time. The contest is all-inclusive: Google Code Jam lets you program in the coding language and development environment of your choice. The Top 500 participants will advance to onsite competitions at a local Google office to compete against those in their region (Asia Pacific; Europe, Middle East and Africa; and the Americas). The Top 100 will participate in the final round at the Google Headquarters in Mountain View, California.
The application that runs the competition is built on App Engine. It was developed by a few Google engineers in their 20% time and is currently serving about 200 requests per second.
If you are interested in participating you still have a few hours to register. Go to the Code Jam site and check out the live scoreboard!