The website http://www.planethunters.org/
lets you look at data from the Kepler telscope and see if you can spot possible exo planets that have been missed by their software. Humans are better at spotting small patterns than the current software is so they're looking for help.
The data is represented in a graphical form and you then click a few buttons and highlight a possible dimming area. The data will be examined by multiple people so the more people find a possible result then the scientists check em out to see if there's anything really there. Check out their Tutorial
for an idea of what I'm talking about.
I have completed my first batch and have already got a candidate that it seems someone else has marked as a possible hit.
Give it a try.