Fon offer a WiFi router which includes a community service in some countries. The idea is that you allow others to share some of your broadband connect via WiFi and in return you can share some of theirs when travelling. The latest version of the router has a USB port and there is an Wiki where applications for the Linux software are discussed. The idea is you can plug in Scanners, Webcams and Printers. But the applicaiton which interests me is to plug in my 3G USB modem, to make a small wireless router.
The Fon hardware is $US49.95, which is less than most 3G routers. 3G modems get a brief mention in the Wiki and there is mention elsewhere of some Huawei H200 and some Sierra modems working.However, Fon do not appear to be shipping to Australia. Also the software is current beta.