I have an iPod whose content seems to have gone wonky. Delete's fail, play-lists won't sync, etc... I wanted to start-over. Unfortunately the iPod itself doesn't have any useful "reset" feature. According to the interwebs you need Apple'siTunes application in order to reformat an iPod. Alright, time to find another solution; and the winner is:
mkfs.vfat -F 32 -I -n "iPod Name" /dev/sdb1
A good old-school reformat. After reformatting and resetting [hold down select and play for 15 seconds] the device is back to its original state.