I think the minimal broadband connection speed for Xbox live should be 512kb download/256kb upload. Even at this speed you might encounter some lag in really crowded servers or gamerooms. And there's also the matter of cost. In my neck of the woods, the main ISP charges about $60 monthly for a DSL service running at that speed, not including the regular phone line rent and other charges. The cable company's service is supposedly just as fast or faster and cheaper, but it's simply not too widespread yet. As it is, online gaming is too much of a luxury down here.