The Home Theater Computer forum on this board has extensive information about the three "currently" available HDTV PC cards: Hauppage HDTV, Telemann HiPix and Access DTV.
Do a search on that forum and you'll probably find out more than you care to know.
I have owned both the HiPix and the Access DTV. Both perform well and record HiDef to your hard drive. Recording is storage intensive at 8.6 gig per hour, but it does allow you to watch OTA HiDef at your convenience.
Currently, the HiPix is on back order but the rumors from Telemann have more arriving in June. The Access DTV card can be purchased at www.digitalconnection.com. Details on the Hauppage are available on their site.
A forum community dedicated to home theater owners and enthusiasts. Come join the discussion about home audio/video, TVs, projectors, screens, receivers, speakers, projects, DIY’s, product reviews, accessories, classifieds, and more!