SuperTV is plugin for XBMC which allows you to watch TV from all over the World, with a fancy EPG. The idea behind was to give the same experience you'd have with a Free-to-Air receiver in a given country. In the rtmpGUI list you'll find lots and lots of international channels that are not listed in the lists for individual countries, and there is blackoutworm's list as well, which comes with lots of always up-to-date sports streams. It does run on your jailbroken Apple TV, as well as on your Mac and Windows or Linux PC. Everything else is explained on the Homepage. You'll always find the latest version of the plugin there as well.