I've belatedly concluded that I ought to switch to rechargeable batteries, instead of schelpping non-rechargeables with me wherever I travel to. My Canon 520 flash consumes Lithium batteries very quickly, so it's high time that I used rechargeables...I found a device that may suit my needs.
The Energizer DUO Charger lets you power up (two at a time) AA or AAA NiMh batteries by plugging it either in a wall outlet or in the USB port of a computer. The charging time varies between 2 and 4 hours depending on battery type. It's small and light...so it's a good traveler. It ships with two Energizer AAA batteries and costs anywhere between $12-15. The downside of this charger is that it only charges two batteries at a time.