The folks at T-Mobile have announced a 4G LTE CellSpot, a device you'll put in your living room to amp up your LTE coverage. At first this might seem like a pretty radical idea - bringing a piece of equipment into your home to ramp up your 4G LTE coverage at no additional cost to you. Pretty neat, yes? But these "CellSpot" devices aren't just for you. They provide additional coverage to every T-Mobile user within range, as well.