Michiel. is Michiel is Michiel is Michiel.
in essence, cobble together or buy a nice desktop system, get one or more Hauppage TV cards (http://www.hauppage.com/), download the Fedora distro from http://fedora.redhat.com and then follow the instructions on http://wilsonet.com/mythtv/fcmyth.php
Some fiddling required, but will turn your TV from an annoying medium with a horrible signal-to-noise ratio into an on-demand entertainment system without commercials, like it’s meant to be.
Check out some of the fun stuff you’ll be able to do:
http://www.mythtv.org/modules.php?name=MythFeatures
I recently built my second one, the machine itself set me back some 700 EUR and the whole shebang was running in less than a day.

