Lifehacker featured a list of their favorite iPod utilities, here's some of our favorites or one's we would like to try.
Floola, is great an iTunes replacement, if you're not an iTunes fan or a Linux user.
iPodBackup simplifies backing up your data by keeping a secure copy on your iPod.
Hack your iPod by installing iPodLinux.
Check out Lifehacker's article for the entire list.