Want a quick and easy way to keep track of what's in your wallet in case it gets lost or stolen?
I've scanned my credit cards, drivers license, etc. (front and back) into a PDF file that I have encrypted into a self-extracting ZIP file (with 256-bit AES encryption and a complex passphrase). I have this ZIP file stored electronically so that I can get to it anywhere in the world. That way, if I lose my wallet I can quickly get a list of what was in it, including the contact numbers on the back of the cards.
The ZIP file also contains a scan of my passport in case I lose it while traveling abroad.
I've added a recurring reminder in my calendar prompting me to update the scan from time to time.