This year at CeBIT Chinese tech company High Tech Wealth (warning incredibly crazy flash header) have developed a solar powered cell phone.

Apparently it can be charged with inside or outside light, and gets about 25 minutes of talk time from 41 minutes of charge time. Which if like me you are not on your phone all day might actually work out just fine. The panel is encased in shatter proof glass so that it will remain safe. Seems pretty interesting.