So this thing, the sun, is capable of being more than just a big, bright, hot inconvenience? According to Soldius, yes. Their cell phone solar charger can give a full charge in only two or three hours in direct sunlight. It uses a technology called Maximum Solar Power Tracking and is compatible with most cell phones: Motorola, Nokia, Samsung, Siemens, Sony Ericsson and most 3G models. Right now, it is limited to cell phones, but expect it to support iPods and PDAs in the future.
Soldius1 Solar Phone Charger [MobileWhack]