[MallyMal]

Check it,

Could someone shed some light on how GameSpy.com and/or XBox Live allows people to login and play games against each other across the Internet? How could I build something similar?

Thanks!

[Eyenovation]

You'd need a HUGE amount of bandwidth, a pretty big size cluster of servers, and a lot of back end programming. Now that I've stated the obvious, I believe there are software apps that you can use for just such a purpose. If I am not mistaking many internet cafes use them. Either way, I'd start with a consultant with VAST IT experience.