GalaxyZoo

Astronomers are inviting members of the public to help them make new discoveries by taking part in a census of one million galaxies.
From the site:
Galaxyzoo harnesses the power of the internet - and your brain - to classify a million galaxies. By taking part, you'll not only be contributing to scientific research, but you'll view parts of the Universe that literally no-one has ever seen before and get a sense of the glorious diversity of galaxies that pepper the sky.