Oh jeez, this is so obvious and brilliant. Put all your credit card, phone, bank, airline, and other customer service numbers in your address book which ultimately end up on your phone if you're syncing.

Here's a bonus tip I do at home with my fire-proof lock box: I leave the key in the lock. If anyone came to steal it they'd just open it, see all I have is a passport and social security card and leave it. Nothing worth stealing in there.