So, our official response on the question of both 3G USB dongles and tethering to an external phone/modem with a data plan is "not supported." That does not mean that we did not build in the plumbing to make this work...it means that we are not going to be your plumber in this case. There are too many 3G modems out there to certify and support and too many carriers adding their own variables. Nothing is stopping anyone from giving it a try .