Here is some of the stuff I have done for use with my mythtv based PVR system.
The system is based on Debian with Christian Marillat's Debian mythtv packages. The system uses cards from the Hauppauge PVR range and the ivtv drivers.
The IVTV driver is a driver for the iTVC15 family of MPEG cards commonly found on Hauppauge's WinTV PVR-150,-250 and -350 cards. I have created some Debian packages to integrate the driver with the Debian kernel packages.