Microsoft's Surface: you kind of have to own one. A new Surface 2 SDK, landing this summer, will sidestep that problem with an input simulator so devs can test their code on any Windows 7 PC. You can tap fingers, place tags, or paint "blobs" for your virtual SUR 40 to interact with, and even fake multitouch gestures by "stamping" a finger in one spot then moving a second one. If the Surface you're programming for happens to be movable (though we're not sure who would put a $7,600 computer on hinges) you can also alter the tilt of the display to trigger UI changes. You'll still need access to one of these behemoths to make sure your wares work in the really real world, but at least the preliminary work can be done on any old laptop or desktop. Frankly, this is something we'd have thought would be included from day one -- as they say, better late than never.