MythTV notes and info
MythTV is a very interesting project, especially to those people with plenty of hardware to burn.
The only Truly cheaper method is to buy a tivo and not get service.
If you add up what Tivo costs + service fees, it's more expensive in the end... But MythTV can do so much more.
You can actually have a distributed capture/playback system based on this thing, and get away with doing away with Coax to your TV and run Cat5 instead!
The Author of MythTV does an excellent job of supporting and developing this system. The Mailing list is one of the more active I've seen, with a generally fast response to help with problems. Just don't ask about the Via EPIA boards to much or you may get wacked in the head for not searching the archives.
MythTV with DirecTV
I wrote up a bit of a howto with links and mirrored copies of the scripts you need to use MythTV with a DirecTV reciever..