How would I go about setting up four 3G (I'll use this as a shorthand for GPRS/EDGE/HSPA etc.) modems, each one for a different network, on my machine so that if my first choice network gives bad throughput or goes down, my internet connection will move to my second choice, until I give up and look for a coffee shop with wifi?
Ideally I'd like to eventually package this set up up into a wireless access point outside of the machine, so 'bonus points' for telling me where to ask about such a more technical development of this concept.