While at a conference last week, we at the Zooniverse team were lucky enough to meet two of the people responsible for the fantastic citizen science project EyeWire. They have created a game where users are awarded points for successfully mapping-out complex and microscopic branches of neurons found in 3D images of the retina. The game-play data collected is used to advance neuroscience research, and also to devise better ways for humans and computers to work together to accomplish challenging tasks. We strongly suggest you give it a go!
For more information you can read their blog.