Try to avoid carrying the following items:
Spare Keys: A lost wallet containing your home address and a spare key to your front door is an invite for burglars. Instead, keep spare keys with a trusted relative or friend.
Receipts: A crafty ID thief can use the limited information on those receipts and merchant information to help fill in the blanks for credit card information.
Passports: It opens up a world of possibilities for an ID thief; they can open up bank accounts in your name or even get a new Social Security card.
Social Security Card: It's probably the worst item you can carry around because once a thief has your name and number, the damage is limitless.
Numerous Credit Cards: The more cards you carry, the more cards you'll have to remember when you lose your wallet. Forgetting to contact just one bank card could be detrimental.
ATM Pin Number: Password cheat sheets are one of the first things a thief looks for when rifling through your wallet.
Hopefully these tips help you. If not, blame 3TV, I got it from them!