Can I use my camera as a webcam on my Laptop?

I have a Nikon D3100 and my webcam on my laptop has very bad quality. Is there a way to hook up the Nikon to my laptop to use for a video chat. Basically I just want to know if there's a way to replace the video on the camera with the one on the Laptop.

The article How To Use Your Camera as a Webcam (http://ml.vu/XxTcYf) tells you how. I got their recommended $25 cable and used it to make my Canon PowerShot digital camera and Sony video camera work as webcams on my PC.