Working with a 3G dongle is quite trivial. It depends completly on the operator 3G coverage. Before buying one make sure you have good 3G coverage, and try with three different operators (Some zones are covered by only one operator).
Note also that as we’re speaking about RF things can fluctuate. One friend of mine goes every summer to his second house in the south of spain, last year he connected hi speed with his mobile + notebook, this year same place, same mobile, same pc, and he had to go somewhere else with the car to get a minimum decent connection to check email.
