Can Xorg be made to use a Laptop as a second monitor for your Desktop computer?

[tweak42]

Given flexibility of Xorg, I hope someone can give a "yes in theory" answer.

I'm trying to find out if Xorg can duplicate what commercial product Maxivista can do but using vnc protocol.

Example scenario:

1. Laptop physically placed left/right of desktop screen.
2. Run full screen vncviewer on laptop.
3. Connect vncviewer to desktop computer. Display will be left/right of local display.
4. Drag application window on desktop computer off left/right of local screen and it appears on vncviewer screen on laptop.

I do know Xorg can do virtual displays via xvfb. Connecting that to x11vnc can create a separate remote session, but I'm not sure if it can be spanned into a local session. Anyone have a definitive answer or clue where to look?

[curaga]

I think DMX could do that natively, connecting those X displays to a single one.