I brought my 4G iPod to the office the other day (along with the USB cable) so I could listen to my music and charge it. The only problem is that every time you plug it into a USB port on a computer it, it starts trying to syncronize — which is not what I want. I needed the iPod to charge, but let me play music at the same time. I fiddled around for a few minutes and figured out a neat trick. If you want to charge your iPod off the USB port of a computer without iTunes: plug in the iPod, wait for the computer to finish recognizing the hardware, then reboot the iPod (on my 20gig 4G, have to hold the center & menu buttons down for 10 seconds). After it reboots it should be charging but not be trying to sync.
If this works for others I’m intrested to know.