If you don't like starting the device automatically in USB networking mode, here is a nice hotkey script. Place as \hotkeys\ALT-U.sh:
Code:
send_string ';debugOn' 'DEL WAIT' 'ENTER WAIT WAIT WAIT WAIT'
send_string '`usbNetwork' 'DEL WAIT' 'ENTER'
Now you can just press ALT-U from the home screen to enable USB networking.