If you are looking for a cheap battery charger then this might just be what you want. I can just plug this into my PC at work! I particularly like the fact that it will charge even one battery.
Official blurb below:
Operates with any functioning USB port and provides all your batteries needs, and also provides an extra USB on the the charger.
Various combination charger - Can charge AA and AAA batteries in any combination, or even charge just a single battery.
2 status indicator LEDs - these indicate when the batteries are charging and when they have been fully charged.
Charge all Ni-Cd and Ni-MH 1.5V batteries
Comes complete with 2 rechargable AA (1400mA) and 2 AAA (600mAh) batteries
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Package Content - 1 USB Charger/Receiver, 2 AAA Ni-MH rated 600mAh rechargeable batteries, 2 AA Ni-MH rated 1400mAh rechargeable batteries, User's Guide