Today only, Woot.com is offering two Cellboost disposable chargers for $2.99, plus $5 for shipping.
If you're not familiar with Woot, they offer a different deal every day--and frequently sell out of the featured product.
If you're not familiar with Cellboost, it's a disposable battery pack that powers and recharges portable devices.
In this case, it powers and recharges any device with a mini-USB port--namely most BlackBerry and Motorola phones. (Here's a complete list of compatible models.)
I've used Cellboosts before; they're insanely handy for those times when your phone battery dies and there's not an AC outlet or cigarette lighter in sight. Throw one in the glove box, another in your purse or briefcase, etc., and you'll never be without emergency power.
When you've used up the power packs, please take them to a recycling center for proper disposal, just like any other battery. End of eco-sermon!