"Other" can be several things. Most commonly, it is files synced to the device that is not music, videos or photos. These can be calendars, contacts, etc. Also, if you use the iPod as a hard disk, any of the files stored on there will show up as "Other". If none of these are the case, try doing a factory restore on the device. It could be that a previous sync aborted before being complete, and the device doesn't know how to handle those partial files. Good luck!