You can use the documentation (rear facing) camera of the Motion Computing CL900 to capture video. This can be useful for field service people to document problems or completed installations. Inspectors can use it to show issues and provide additional documentation for an inspection form.
I downloaded free software from NCH Software which let me setup this functionality in just minutes. You can get the software here: http://www.nchsoftware.com/capture/index.html
When you first start the software, it will use the webcam by default but you can go into the Options and under Webcam/Capture Device, choose USB 3M DocCam. That's it and you can start capturing video. I found that using .wmv where it shows 'Record Web Camera as:' gave me the best quality video playback.
If you have other questions about using the CL900 cameras, you can check out this article in the Motion Computing Knowledge Base.
Enjoy!