A family member is working with the University of Bristol in developing a non-invasive cat recognition technology called "My Cat’s Photo-Id". (So far, it's been recording the daily movements of more than 2,000 individual penguins as they go to and from the sea, so it's pretty effective!)
Once it's developed, cat owners (and rescues) will be able to ID their cat(s) with a standard camera (the photo would be uploaded to the internet). The cost will be between £5-£10 and the ID would complement micro-chipping and act as a back-up when it fails - and it would certainly assist in the lost and found process.
I'm not sure of all the ins and outs of yet, just thought I'd post here to see what you think.