When you first realize your wallet is missing, "retrace your steps," advises Lieutenant Jan Easterling of the Dallas Police Department. Often cash is plucked and the wallet dumped. Next, says Susan Howley, a director of public policy at the National Center for Victims of Crime, in Washington, D.C., "call the local precinct and file a police report. And get that report number, for the bank and credit-card companies." Then, if you have an American Express card, call Amex. For $29 a year, the company will cancel all your ATM and credit cards, arrange for new ones, flag your accounts with a fraud alert, and even (in some states) replace your driver's license and passport — saving you hours of waiting on hold. Otherwise, Howley says, cancel and replace each card on your own. Then contact all three major credit bureaus (Equifax, 800-685-1111; Experian, 888-397-3742; Trans Union, 800-916-8800). Each will file a fraud alert and send you a free credit report to monitor suspicious activity.