MBNA has the best one-time-use credit card numbers program. You can choose to do it either with an application you keep on your computer, or through their website (unlike some that force you to download an app that annoyingly pops up everytime it decides you are going to make a purchase). They also let you choose the maximum limit AND the expiration date. Once it is used, it can be used again until the expiration date, but only for the SAME merchant that first used it, and only up to the max limit you first specified. If you have reason to believe that your card is going to be fraudulently charged in the future, you can simply kill it "on the fly" instantly, to prevent any further charges on that number. This is most useful when you sign up for a trial service, then call to cancel it, but are worried that your request to cancel may not be honored, and that they may try to charge your card the full amount anyway without your permission. Excellent service.
Nack