The next big thing in mobile internet technology is location. With GPS-enabled smart phones like the iPhone, Blackberrys and Android phones, software like Google Buzz, Foursquare and Gowalla, and location-enhanced options coming to Twitter and Facebook, its becoming easier to check in to the cyber world while on the go, and follow your friends in real time.So how does that pertain to musicians? We're seeing all kinds of interesting uses here in Austin at SXSW: official convention updates and breaking news sent to SXSW registrants; bands sending up-to-the minute, location-enabled info to fans