Study asteroids.
Berkeley Open Infrastructure for Network Computing, has LOTS of projects.
Protein folding is being studied for cancer research.
Android app that works on phones other than HTC that will use your phone for a project you pick. Only uses the phone when it's plugged in and WiFi is available.
problems being solved will be chosen by an advisory board. The goal is to help unlock the genetic mysteries of diseases like AIDS, Alzheimer's, malaria, and cancer
Has a few projects.