I was thinking, while I was at work today, that I would love to use the droid to test connectivity of a data drop that I moved. I thought it would be cool to be able to take a cable with the USB on the phone side and RJ-45 on the other, and when connected, that would be the priority connection. If there was no connection to the network, then other connections (wireless or 3G) wouldn't work.

ANything like this exist?