Innobec Technologies is a little known company who makes quite the underdog of a product, SideWindow. Sidewindow transforms your unused, dust collecting, outdated PDA into an additional display for your Windows based computer. I use it as my 3rd display currently and have it displaying my CPU temps of both cores by dragging Intel Thermal Analysis Tool onto it.
Sadly the author is having trouble turning a profit on his creation, and has no plans for Vista support. So those of you die-hard XP users out there can give it a try and be sure to tip the man a couple bucks if he decides to release it open source, its worth it!
SideWindow supports standard (240×320) and high (480×640) resolution devices such as the Dell x50v or the Toshiba e805, in either Landscape or Portrait mode. Intermediary resolutions are also supported, and can be configured easily . You can interact with the applications on the SideWindow using your mouse, fingers or stylus.
This looks really cool. Unfortunately, it seems like it only supports WinCE devices. It would be cool if you could use a Palm with this as well!
[...] This nice ghetto rig was brought to you by a laptop with S-Video out going to a portable DVD player, as well as a PDA with Innobec SideWindow. [...]