How to use my Nikon DSLR as a webcam/video recorder on my Macbook?

I want to record a video and see what I'm recording on my Macbook, I know it's possible for Canon DSLR's, using the Canon EOS Utility program, is there something similar for Nikon [D5000 in my case].

Yes, Nikon supplies a programme for tethering, or you can tether via adobe lightroom. Personally I like NK Remote which I use with my d7000. Full control over your camera and its very easy to use. With the d7000 it works of the USB connector, not sure if the d5000 has it though the newer d5100 does

edit: Heh, checked on their website, the d5000 is supported. Just do an internet search for NKRemote and you'll find it.

I doubt that using a $850 camera as a web came is a good idea in any case.

The image quality is far too high for the standard broadband Internet services and besides, your camera will shut down once the CMOS sensor gets too hot (about 5 to 10 minutes)

For under $35 you can buy a proper webcam, but as I recall, you MacBook has a webcam built-in to it.