Galaxy Zoo

I found this on Bad Astronomy and thought it was pretty cool:

A website called Galaxy Zoo allows users to classify galaxies. Visitors to the site are shown images of galaxies from deep space captured by a robotic telescope. By answering a series of questions, visitors are able to help the scientists who run the site classify these galaxies based on their characteristics. It's easy, fun, and many of the galaxy images are absolutely stunning. It's a great way for "ordinary folks" like most of us to use real world data participate in real world science.

Their goal is to classify 1,000,000 galaxies by Sunday, so I'm sure they could use all the help they can get. But I should warn you...it's surprisingly addictive.