What video cards allows different content to be outputted to two different sources.?

I want to build a computer with a video card that would allow me to see one type of content on the VGA screen, and output a different content (like a movie) to S-Video or RCA. I should be able to control what is shown on the video screen from the VGA screen...I'd like something resonably priced as well...! Thanks!|||i dont own nVidia but every ATI card since my old X800 can do that from Catalyst Control Panel...