USB AA NiMH and NiCd Battery Charger

Any USB port can supply 5V at up to 500mA. The USB standard specifies that a device may not use more than 100mA until it has negotiated the right to use 500mA, but apparently no USB ports enforce that requirement. This makes the USB port a convenient source of power for devices such as this charger.

USB AA NiMH and NiCd Battery Charger: [Link]