Everyone seems to love the USB Cell (the battery that can charge via USB ports), so they've decided to expand into the world of cellphones as well. It's the same idea as the original USBCell—take a battery, put a USB port on it, wipe your hands on your pants and call it a day—but fits into cellphones instead of MP3 players.
Now to charge your cellphone, all you have to do is take off the back, plug in the extendable USB plug and you're in business. Much easier than buying a spare charger for your phone, right? Right?
Product Page [USBCell]