I have done this before, but it stopped working. The first time I hooked it up, I would play an AVI in media player on my laptop's screen (not full screen mode, just a small window) and media player would send a signal to the S-Video port also, so the AVI was actually playing in two places - the small window on the laptop, and full screen on the TV. Life was great.
Then I made the mistake of closing the laptop cover while the video was playing. It stopped working.
The laptop is a Dell Dimension D600 laptop. I can extend the desktop over to the analog TV the same as one would with two digital monitors and move Media Player over there in full screen mode but the quality is terrible. I want to get it working the same as before, with Media Player sending the "extra signal" out the S-video port.