6126&allowFullScreen=true” width=”400″ height=”330″ AllowScriptAccess=”never” base=”.”/> Launching today, MTV’s Backchannel is a very cool-looking social game synergizing a very silly product— specifically, the network’s “reality” show The Hills . As the title suggests, Backchannel’s a chat interface that runs live online while a Hills episode airs on TV; players quickly post their witty