Just something to keep in mind - according to the agreement that each vendor agrees to who accepts Visa/Mastercard/AMEX/Discover the vendor may NOT charge a surcharge to use a credit card. They are perfectly well allowed however to offer a discounted cash price but it must be stated clearly.
For instance, I sell copiers, if I tell you that this copier is $348.00 and you hand me a Visa card I can't charge you 3% more since you are paying by Visa. I CAN however say that the price is $348.00 and the cash discounted price is $338.00
It's really just symantics but it's something that consumers should certainly be aware of, if you find someone trying to charge more for CC purchases be sure to report them to the credit card company.
Vendors are also not allowed to require a minimum purchase for credit card usage, I see signs often that say minimum $10 purchase on credit cards, makes me angry that some people play by the rules but not others