The fact that modern smartphones still actually make voice calls may well come as a surprise to many users happy to use their mobile devices as pocket-sized computers. Carriers, on the other hand, seem content to keep the "phone" in smartphone. AT&T's Randall Stephenson told an investor conference this week that he sees a time in which carriers offer up data-only options for subscribers -- a time that may well come in the next two years or so. The CEO said he'd, "be surprised if, in the next 24 months, we don't see people in the market place with data-only plans." It's hardly an announcement, but it certainly comes from a guy who knows a thing or two about where the industry is headed.