After Time Warner eliminated all watchable ClearQAM from basic cable, we bought an HDHR Prime cableCARD tuner for my MC box. So that my wife can watch her shows on her HDTV, we got a 4GB XBox 360 (the slim black one) and set it up as an MC extender. Wow, it works great and was quite easy to get going. Now she can watch John Stuart in fully copy protected HD from my MC box in the livingroom.
Of note, ShowAnalyzer does not work on copy protected shows, so we have to manually jump over the commercials. Curse those media fat cats.