That's an interesting thought.

Over here (UK) if I took a laptop to a friend's and hooked up to their router it would work just fine.

If I took my router and connected it to his telephone line it would take a while to sort itself out with the ISP, but would then work OK. It would, however, need setting up as a new piece of hardware on his ISP account. It would not work with my credentials as the telephone line is wrong.

OK, I can have mobile and mobile wireless accounts & equipment, but the basic "home" or static offerings are tied to your account location.

I would have given the ISP a hard time by now, but luck with getting through their first line support.......................