Some interesting points made here
I'm finding the one iTunes per device rule is a serious pain.
To encode for this massive undertaking I'm using my two Son's and their PC's to build the library.
The Main PC (mine) with my Wife's account is set to sync with the Touch. Anything created on the other PC's must be moved here for successful syncing.
I can't even use my administrative account on the same PC while it is connected. since it will delete itself.
Example, you went on vacation...and met some relatives, friends and stayed at their house, you decide to snag some old photos from them..iTunes will promptly come up with a "this iPod synced to another account..." error message and the proceed to delete all your music.
So in an instance like this were I to visit my Uncles and Aunts in the "Old Country"
I'd need a laptop or a separate USB drive. I may have 22Gb free on the Touch but that is useless to me since I must use iTunes to move data in and out.