Valve just announced Big Picture, a Steam interface just for your TV. It was added in the latest client update, and lets you play your Steam games on your HD TV. If you've always wanted to use Steam outside your PC setup, this feature lets you do that.
Setup is said to be very easy. All you need is either a laptop or PC with Steam and a HDMI cable connecting to your HD TV. Mouse and keyboard is needed, but a game controller can also be used to navigate/play through Big Picture. This is Valve expanding in a way. Out of the PC monitor and into your living room.
It's a pretty neat feature. If you have a strong Laptop or PC, you can treat it as another console by placing it beside your TV to play games. Big Picture is currently on its beta stages, but you can give it a shot now by opting to join the beta. All you need is Steam installed to join. The beta is currently for PC running a Windows Vista, 7, or 8 Operating System. Mac version of Big Picture is not yet available.
For more information about Big Picture, click here.