If your house loses internet, or you're taking your 360 on the road, connecting to Xbox Live can be a hassle. Oh, unless you have a 3G phone and follow this handy guide!
It'll show you how to configure your phone, a laptop and your 360, then use them to commandeer an AT&T 3G signal and route it to your console, enabling you to connect to the service and even play games online. You won't get the best performance, it takes a little fiddling to get it running and apparently voids a warranty or two, but hey, some people are so desperate for this kind of thing that warnings will mean nothing.
3G For Xbox Live [2old2play]