My friend recently set up his Replay TV to connect to his PC over Ethernet.  He allocated a 120 Gb drive on his PC to his Replay device.  He also spent a couple of hours converting a couple of dozen of his DVDs and tapes he owns over to this PC hard-drive.  This now makes it possible to play them on demand.  

This is getting closer to what I want:  a simple device (and remote control) that connects my entertainment center to my PC.  Nothing fancy, just hardware and some light software.  This would allow me to easily store all the content that is delivered to my house or any movies/music I play on my DVD/CD player on an inexpensive drive for personal use later.  I could select from a variety of extremely low cost programming guides via the Internet (this competition would allow the guides to get better, faster, and more powerful quicker).   The interface doesn't have to be that different than a standard PC interface (on HDTV at 1080i, a PC interface is extremely nice and 30-40″!).  If this was built into a home theater receiver, that would probably work too (it would only require that a couple of input jacks — for all three major modes of input — that route through the computer's PVR hard-drive). [John Robb's Radio Weblog