Gee, following that line of thought, you could do a respectable wearable computer for not much more than $1000! (IBM's was $5-10,000.) With voice input using off-the-shelf software, too. Did you notice that in this
picture, the guy seems to be holding a mouse-like device?
* This new mitsubishi display device for about $400 for a virtual 10" display
* The IPAQ hx4700 vga Pocket PC attached to your belt ~$700
Or for a few bucks more, you could build this around one of the new handtop PCs. That would even allow dication transcription through Naturally Speaking voice recognition software.
* A bluetooth handheld mouse product. Surely there's one out there. The idea is, for example, something like this
* A driver to allow the handheld mouse work in place of the IPAQ touchpad
This would be a pretty neat setup. You could use it in private, on Halloween, or even in public if you ignore all the snickering and pointing!
Quick -- Somebody tell the folks at Engadget.com about this. I bet they could have a working model ready in a week!