Nokia N/E series - useful tool
 

SmartConnect - Birdstep

basically setup the order of the internet connections that you use and it will deal with it for you without you having to worry about it. . Its on a free deal so grab it while you can.

e.g. I use wifi at home, Voda Internet when out, wifi at MIL and a seperate connection at work. this will connect in a specific order i define moving on if a connection is unavailable