Help other developers out by testing their web applications, iPhone, Droid and other mobile applications, iPad applications and even gems and plugins.
When you're done testing other developers' applications you earn points. You can also earn badges and lend your expertise in forums. The more you help the higher you rank in the leaderboards.
Now that you've earned some points, you can create your own tests. Need some beta testers for your new project? They're only a click away!