When you have a new credit card, don't sign your name on the back, instead write your driver's license number. The clerk will have to ask you to see your driver's license but that only takes a minute to check. If your credit card is stolen no one can see your signature to use it.
This page contains the following solutions.
This is something to think about; your old card is beginning to peel and show wear so you order two new replacement cards with the same numbers ... you may have an embarrassing situation!
On the back of your credit card, instead of your signature, write "Photo ID required". That way if it is stolen, no-one could use it (unless they are an identical twin). It's still important to report it lost or stolen, as this would not protect you in a phone or mail order situation.
If you have a tendency to use your credit cards impulsively, try this: put them in a watertight zip-lock baggie. Drop this baggie (sealed shut) inside a larger baggie (or another type of container) that is filled with water.
Call your credit card company before you leave. Let them know where you're headed and what kind of purchases you are likely to be making outside your normal spending pattern.