Apple does not recommend running disk utilities like Norton Speed Disk, Disk Scan and Disk Defragmenter. It’s not really needed as the drive is not written to and erased nearly as much as a typical hard drive.
If you’re emphatic about cleaning up your drive it’s best just to do a full Restore with the Apple Software Updater.
This reformats the drive (defragmenting it in the process) and has the added benefit of creating a new clean iPod database which over extended periods of use can get corrupted.
