Tokyo-based electronics company OTAS is selling a lithium-ion battery for the iPhone 3G that comes with an integrated mini solar panel [JP]. The so-called LC-1500 is housed in a leather case. OTAS says one charge with solar energy takes 13 hours whereas charging the battery via mini USB takes 3 hours.
The device measures 125x64x25mm and weighs 100 grams. OTAS is selling it in Japan only (price: $60).