Getting An MPEG-2 Stream From Digital Cable?

Alex Perez asks: "I recently moved to an area where AT&T was offering digital cable. I've subscribed to the service and I love it, but I want to find a way to get the MPEG-2 digital video (and some sort of audio) stream out of the decoder (It's a Motorola set-top box) and ultimately into my PC as an MPEG-2 stream so I can record shows in true digital. Technically, I know it's possible. Is this legal for personal use? I can make video tapes of my favorite shows, but the quality is unacceptable in my opinion. What are my options, here? Has anybody else attempted to do this? I'd love to find a way to get a digital video and audio stream, but I don't want to re-invent the wheel."