Until very recently, Microsoft wasn't known for making hardware. Sure, it put out the occasional Zune, but most of the tech running Redmond's desktop and mobile operating systems traditionally comes from its partners -- the Surface being the exception, of course. According to the Wall Street Journal, Microsoft might consider making that exception a rule: some of the firm's part suppliers say that the company is experimenting with a smartphone design of its very own. Folks familiar with the matter say the device in question is between four and five inches, putting it in a sweet-spot that's larger than the iPhone 5, but not quite as daunting as a Samsung Galaxy Note II. Don't get too excited, however, sources aren't sure the if the device will go into mass production, and Microsoft is expectantly tight-lipped about the rumor. Still, we wouldn't scoff at a smartphone with a build quality to match the Surface -- though it might rub some of Redmond's hardware partners the wrong way.