Vladimir Ralev 's TabletPC 1.0 Advanced Remote Control allows user to have a Pocket PC as an input device for desktop or laptop computers.

"Despite the cool graphics this application is surprisingly useful. I tuned it to behave mostly like a touchpad, but I did some extensions so you can use it in graphics design as a tablet input device for your workstation PC. When you get on it you will find it great for use with the top-line image creation / processing software (Adobe Photoshop, CorelDraw, 3D stuff etc.). The background image is created this way. I even use it to upload this entry on CodeProject."

Note that the server side on the computer will open and need access to a specific port (TCP 333), so if you're using a personal firewall, some tweaking will be needed.