What are you trying to do ? If you use youtube capture mode, it moves a lot faster than if you capture on the desktop and trying to upload on there. Then you can download your movie off youtube ? idk. Try a digital camera ?
You may be able to get a satisfactory solution with a high res webcam that can do 30fps at its highest res.
Use a lower res and increase the framerate.
Try it (lower the res, increase framerate) on your current webcam to see what sort of improvement you can get.