Somehow I've ended up with four iPods, each charging… somewhere around my apartment. That scattered AC situation will end soon with the Griffin PowerDock, which will let me charge up to four iPods at a time via one AC line for $70 in March. There's also a two-iPod version coming in June for $50, but even if you have only two iPods I'd get the four — you know you'll be buying more iPods or iPhones. All of them come with all the appropriate snap-in dock adapters.
We tried to talk them into a version with USB out and some sort of switching so you can charge and sync without moving the iPods around. They promised to think about it.