Kanex DoubleUp — Two-Port USB Wall Charger for iPad and iPhone
As the title suggests, the Kanex DoubleUp is a wall adapter that accepts two USB cables. It's powerful enough to charge two iPads relatively quickly, thanks to each USB port's 10.5-watt output, and it has helpful status LEDs on the front to let you know if your device is fully charged (green) or still charging (orange). I like that it's small enough to toss into a bag on trips.