I have an Asus-something wi-fi router with USB2 socets. It can provide full 500mA for my 3G dongle and it can run Linux wrt instead of the software it came with. With that setup I have a 3G-to-wifi combo (it's not a portable solution, but there's no wired internet at the place to start with). I don't use it anymore though, I gave up a long time ago due to the low quality 3G networking. I may try again when the HSDPA (aka turbo-3G) coverage has been improved in the area.