MythTV - HDTV Personal Video Recorder
How to build your own HDTV PVR - MythTV
Want to control your TV viewing? Don’t want to let TV Broadcasters prevent you from fast forwarding through commercials? Do ya?
Take control of your viewing habits (or just read -a great alternative, by the way). Build your own PVR and watch when you want and how you want.
This is a very detailed method of building your own PC based PRV. Not for the faint of heart, but very do-able.