HTC is supporting Android-based volunteer computing through a new program called Power to Give. This is described in two YouTube videos: one about how to participate and another about the science being done.
BOINC has been working with HTC - one of the world's leading smartphone manufacturers - to bring volunteer computing to Android devices. On February 24th we'll release an exciting result of this partnership - stay tuned!
The CONVECTOR project is open and looking for volunteers. The project, based at the Czech Technical University in Prague, studies the optimization of mechanical systems - currently, a system called the "52-bar truss".