Before my wife and I went to Mexico last October, we made a list of all the important numbers in our lives. We had credit card numbers, telephone numbers for credit card companies, passport numbers, bank account numbers, insurance policies, retirement accounts, drivers license numbers, online banking passwords etc.
We wrote these all up on the computer, printed out a single copy and deleted the computer file. We then gave it to my parents to keep in a safety deposit box. If anything were to happen to one of us or if our wallets were stolen, there is a single place we can go to get all the important numbers we need.
This took us a very small amount of time to put together, but if our records were destroyed or some other disaster occurred, it would save hours and hours of difficult searching.