Okey, is there any way I could use my screen in the same way as the webcam? Not screen sharing, but as a webcam in video chat? Thanks!
No, this is not possible. For this you need a webcam.
Why not, if you have Windows 32bit: http://www.willingsoftware.com/help/howto.shtml#29
That utility won't allow a standard computer montitor to be used as a webcam.
Select desktop as a video source, then enable the 'Video Output' feature. Voila.
Ok....if you say so.