Streaming Video?

Does anyone know if it is possible to set up your camera like a web cam to capture streaming video. I have the cyber shot dsc s50 and I can't bypass the pc mode screen.

Also, can a non-mavica sony that has mpeg capability take constant video by holding down the button until the memory space is full like the mavicas can? (I've tried this but I was hoping for a setting to adjust that would enable this feature)