I'm looking for the software that can broadcast image/sound from my computer display, acting like that webcam.
Of course, pointing real webcam into monitor is not an option, because it reduces quality a lot.

Vncviewer and vncserver. There's a few variations but any of them will get the job done.

>>2
well it would do the work. but op possibly wants something that "emulates" a webcam, so you can output your desktop to someone in skype for example.

actually i would be interested in something like this too.

I found the solution. ManyCam allows such video stream.
For a sound I'm going to follow these advices: http://l4cs.jpn.org/gikopoi/manual/en_flash_radio_manual.html

ah cool. thanks for sharing!

i use webcammax for this