HN user
That might be doable. One of my fellow students designed a jigsaw puzzle solver that worked by looking at the shape of the piece, rather than a picture. However, I have worked in this kind of area and if you can guarantee little rotation, working out the translational offset isn't too bad. I'll give this some thought.
If you like the look of it, you can find the app itself at: http://itunes.apple.com/WebObjects/MZStore.woa/wa/viewSoftwa...
I do seem to remember a Pratchett quote that conjurers amaze you twice - once with the trick and once with the trickery.
I certainly hope so. We got taught by John Daugman, who's done some amazing stuff in Computer Vision. It's brilliant for us to be able to do something like Sudoku Magic in a mobile phone. And we have plenty more ideas to come!
We actually met some people doing something like this in Cambridge when MagicSolver was just starting - a group called imense (http://www.imense.com/). They have an automated picture tagger. You give it a picture of a field of sunflowers, for example, and it comes up with 'flowers, nature, field, ...'. I imagine that if you made it domain-specific (your PCB example), you might be able to actually classify the objects.