Video capture card or external video capture device, got mine for around $50 bucks, you can get less or more expensive depending on your budget.
Check here
http://shop2.outpost.com/category/Outpost/PCtab/Video+Imaging/Video+Editing+&+TV+Tuners/Video+Capture/?site=sr:SEARCH:MAIN_RSLT_PGI got this one and have had no problems after buying a cheaper brand that didn't work properly
Leadtek WinFast TV2000 XP Expert
Price: $ 59.99
Leadtek (TV Tuner):
Outpost #: 3970948
Turn your PC into the best personal digital video recorder with video editing and authoring. It is the smartest and most effective way of turning your PC into a high definintion TV and FM entertainment center.
Features:
It allows broadcast TV viewing, stereo FM radio, live video display and video communication on a PC with the finest quality and optimal performance. Moreover, you are able to access rich variety of information at no cost without an Internet connection through todays data broadcast technology.
More
http://shop2.outpost.com/product/3970948?site=sr:SEARCH:MAIN_RSLT_PG