The USBCell seems to be available for ordering now in the US. For those of you who haven't seen this yet, it's basically a rechargeable AA battery, except it has a built in USB plug so that it can recharge via the USB ports on a computer.
Capacity is only 1300 mAh, which is a little over half some of the highest capacity rechargeable AA batteries…but that's somewhat understandable, considering the USB plug takes up about a third of the battery.
Of course, the nice thing is that if you travel a lot, using USBCell batteries means a battery recharger is one less thing you need to carry around. I figure that pairing these batteries with the Microsoft Wireless Laser Mouse 8000 gets you pretty close to the ideal notebook mouse. No wires since the mouse uses Bluetooth, and you'll be able recharge via the laptop itself when needed.