Another possibility might be to live-broadcast the laptop screen over the web using a service like www.justin.tv. I think Moorea (a forum member here) is doing this with WoW. Maybe you could broadcast the laptop screen and watch the results in a browser pop-up on the desktop machine. I have no idea what the latency or frame rate would be or how much it would bog down the laptop. Maybe you would need to buy a screen capture card to get decent performance.

Moorea's broadcast:

http://www.justin.tv/mooreatv/old