An interesting effect of rising gas prices ...

... old-fashioned gas pumps, can't handle the increase.

Mom-and-pop service stations are running into a problem as gasoline marches toward $4 a gallon: Thousands of old-fashioned pumps can't register more than $3.99 on their spinning mechanical dials.

The pumps, throwbacks to a bygone era on the American road, are difficult and expensive to upgrade, and replacing them is often out of the question for station owners who are still just scraping by.

Many of the same pumps can only count up to $99.99 for the total sale, preventing owners of some SUVs, vans, trucks and tractor-trailers to fill their tanks all the way.

Bummer! Guess that means that gas prices won't be allowed to go over $3.99. Right? Yah, I wish.