ZoneScreen

ZoneScreen is a tool for extending your desktop workspace using displays of network connected computers or portable devices like Pocket PC. Like VNC, ZoneScreen is able to mirror local desktop to another computer in the network. The main difference is that it also allows extend desktop, just like the case when you have second monitor connected.

All you need for ZoneScreen to work is network connection between your devices (your computers are both connected to the same network, or connected directly with cross-over cable or 1394 firewire cable, etc). In case you are using Poket PC, you may use connection provided by ActiveSync (using cradle cable, IR port, etc).