The $30 is a near-perfect solution for charging on the go. Don't let the name fool you; its two USB ports are in no way Apple-specific, although the device does come with an iPhone/iPod charging cable. But you can charge any USB-powered device from this slick little charger.
If you're in a hurry to get your phone charged up, plug it into the clearly labeled Fast Charge port. Secondary devices can charge from the other USB port without hindering charge times on the fast port. One caveat: the Fast Charge port produces a background hum if you plug your iPod into it while playing music, so be sure to use the standard port for situations like that.
I've been using the Dual Auto Charger to keep my BlackBerry and my iPod fully juiced for a couple of weeks now, and this simple charger hasn't let me down. Better still, it's slim and compact for easy transport, adding a scant couple of ounces to my travel bag.