Galactic

Because I participated in their first experiment, I just got an email announcing Galaxy Zoo 2. A while back, some astronomers set up a robot camera that surveyed the sky for galaxies, creating a huge picture database. They need them all to be classified; elliptical, spiral, mergers etc. It turns out that humans are still better than machines for this, so that is where the random People of the Web come in - yes, you too can be a scientist for half an hour. So I hereby encourage you to sign up and get classifying. No expertise req'd; just read the help, and don't worry about making mistakes as the same pic is shown to multiple people and some magical maths corrects all the errors.