Saw an article this morning about some gas station operators refusing to accept credit cards for gas purchases. Merchants pay the credit card companies a percentage on every transaction, and since it's a percentage rather than a flat fee, the cost per gallon has steadily increased until it is now running around 10 cents per gallon (average interchange fee is between 2 and 3 percent on most major credit cards).
I can see it now, not only will a fill-up cost over $100, but everyone will have to either go back to carrying large amounts of cash or step into the wayback machine and start writing checks again (I'm not sure I remember how to write checks).
Jerry