Building a portable usability lab

I want to built a portable “usability lab.” Something more capable and professional than the single camcorder we’re using.

  • It should merge 2-3 video inputs into one recorded image.
    It should have a way to reference scenes (timecode or whatever)
    It would be cool if it could capture notes and link them to the footage
    It should be portable
    It would be great if it was digital
    It would be great if it didn’t require multiple pieces of equipment
    It should be easy to use

What hardware and software should I consider?

I found this, which is marketed as a product for home-security:
http://www.grandtec.com/magicguardusb.htm

It merges up to four inputs onto one image (tile or picture-in-picture) and outputs MPEG to your PC via USB. Only $250 at Smarthome.com

Maybe it could also track things like eye movement and mouse movement while tasks are being performed. I think that there are exotic tools for doing this, but I am not sure. Anyone know?