I picked up the Griffin Technology PowerBlock on a whim. Good impulse purchase! It's a very compact, well built, folding plug USB charger with a compact iPod USB cable. It'll charge any relatively modern iPod. It's much more compact and portable than Apple's USB charger, it's less expensive, and it comes with a iPod cable as well.
Since my phone also charges via USB, this device replaced my phone charger and an awkward old firewire charger. Sweet.
See also: Griffin does me wrong, then makes up.