Steps that I learned that transfers files to Ipod Touch via USB cable
Run Ubuntu 10.04
Must transfer one file to Ipod using Itunes and Windows
(hold your nose while doing it)
Install GoodReader app via App Store
Connect Ipod (duh)
In GoodReader press Wifi Transfer (icon on lower left corner)
Must use web browser connect to port indicated
(mine was 192.168.2.2:8080)
Now use Nautilus option: "Connect to Server"
then select: WebDAV (http)
enter server: 192.168.2.2
enter port: 8080
A new incidence of Nautilus will open
WebDAV will be seen through which files can be transferred to ipod.
Works with many file types: pdf, mp4, mp3, etc.
(Don't know what browser connection must be done first)
Hope this helps.