Unlock your car

This may come in handy someday. Good reason to own a cell phone:
If you lock your keys in the car and the spare keys are at home, call
someone at home on their cell phone from your cell phone.
Hold your cell phone about a foot from your car door and have the person at your home press the unlock button, holding it near the mobile phone on their end. Your car will unlock.
Distance is no object. You could be hundreds of miles away,
and if you can reach someone who has the other “remote” for your car, you can unlock the doors (or the trunk).