Admittedly this looks and sounds really low-tech and cheesy, but I'm totally going to get one when it comes out. It's a portable USB charger from a company called Meggaboom that you power by winding the handle. Never worry about having spare power again - just remember to bring an extra USB cable with you.
Fully wound, it'll re-charge an iPod one and a half times. It's got tape on it because it's an early prototype, so we don't know how many winds it takes to recharge its internal battery, how long an iPod re-charge takes, or if you can wind-and-charge simultaneously. In all events, it'll go on sale sans tape (hopefully) in April for $60.