Must of the cheap USB webcams I've seen are pretty low resolution, and the picture is kind of dark. Doubt you would be happy with the results. Only way to really know is crack it open and see what's inside. Might get lucky and find a regular CCD camera and video signal in front of the USB stuff, and just need to add power to the camera and a video cable. I've never been into webcams (dial-up internet, not much for chatting either), so have no idea what's inside.
As mentioned previously, I was given an old ALPS webcam, but it need a video capture card, and it was direct video/audio out, so no big deal. The picture is surprisingly good in daylight, but useless at night.
Anyway, if your webcam is basically junk sitting on a shelf, and you thought to give it some new purpose, nothing really to lose if it gets destroyed. Open it up, post some pictures of the guts. We'll be better able to give suggestions.