Ok, so far we know figured out:

    - Use a command to use the isight (isightcapture?)
    - How to incorporate it into the login (after password, before *Finder)

Though we still need to:
    - Have some sort of image recognition built into this application
    - Have it actively scan until the image is OK
    - Continue to the Finder

Man, I wish we had a programmer lurking on the board...

* Up for debate
MacBook 2GHz Intel Core 2 Duo w/ 2GB DDR2 RAM & 120GB SATA 5400RPM HDD
Canon Rebel XTI
Google Cr-48 Beta Laptop