Darren Hobbs wrote that he lost his wallet, and he’s struggling to remember what’s in it.
One piece of advice that I read (and followed) a while back was to make a photocopy of the contents of your wallet (all the cards, etc) front and back, and store them seperately, in a secure place.
Obviously in some ways this makes the possibility that someone steals your CC# slightly more likely, but it also gives a nice record of what is there, what numbers to call to report lost/missing cards, and so forth.
If you want to be extra secure, black out the CCV and expiration dates on the photocopies and make a photocopy of that, and destroy the previous photocopy.