About 6 months ago I wanted to get a PVR like Tivo... but being cheap I didn't want to pay $12/month for the service. So I spent a lot more money and started down the road to build a PC based PVR.
I started with a Hauppauge WinTV-PVR 250 for about $150. The installation of the Windows software required me to upgrade to WinXP (another $100 bucks)... and after running like this for a while with poor programming support and frequent weirdness I went hunting for an open source solution.
I then found MythTV (http://www.mythtv.org). I tried to install it on RedHat 9 and Fedora Core without any real success... it was tough to get the PVR-250 working right.
More searching I found Knoppmyth (http://www.mysettopbox.tv/knoppmyth.html), which is a mythtv install based on Knoppix. After downloading the ISO image and going through the auto install I had my backend up and running within minutes. Awesome!
Note: Currently I am running R4V3. I recently attempted to upgrade to R4V4.1 but my via chipset on the motherboard is giving me issues with the new version. I believe R5 should be out soon so I may try upgrading again when the new version is out. The new version will support creating DVDs from the recorded shows.