webhead, I think your talking about the USB port on the front of the touch screen radios. right? my current rubicon has that and it is indeed for uploading music to the hard drive.
What i'm talking about is the port that is added to the center console when you add the connectivity group. You don't need to upgrade to a radio with a hard drive to get this port. (but you do need to upgrade to the sirius radio).
woomdawg, I read something on a forum that people were getting this usb port added by the dealer. (i dont recall details of what year or what radio they had).
It appears it works with ipods, but don't know about thumb drives. Thats what i'm trying to figure out.