What That Little Ball is For on your Gas Cap [PHOTO]

Do you have this little ball-type thing hanging off your gas cap, too? If you didn't know, here's what it's for.

More and more cars recently have had ways to make you not forget your gas cap at the gas station from having a handy place to put them in the door to your gas from basically tethering them to your car itself. This one happen to have this little ball thing hanging out and, viola! Look at that. Fits right in and I don't have to worry about leaving the gas cap at some random place. Neat!