Pretty neat idea. Never thought of it before.

Put your car keys beside your bed at night
Tell your spouse, your children, your neighbors, your parents,
your Dr's office, the check-out girl at the market, everyone you run
across. Put your car keys beside your bed at night.
If you hear a noise outside your home or someone trying to get in
your house, just press the panic button for your car. The alarm will
be set off, and the horn will continue to sound until either you
turn it off or the car battery dies.
This tip came from a neighborhood watch coordinator.
Next time you come home for the night and you start to put your
keys away, think of this: It's a security alarm system that you
probably already have and requires no installation. Test it. It will
go off from most everywhere inside your house and will keep honking
until your battery runs down or until you reset it with the button
on the key fob chain. It works if you park in your driveway or
garage. If your car alarm goes off when someone is trying to break
into your house, odds are the burglar/rapist won't stick around.
After a few seconds, all the neighbors will be looking out their
windows to see who is out there and sure enough the criminal won't
want that. And remember to carry your keys while walking to your car
in a parking lot. The alarm can work the same way there. This is
something that should really be shared with everyone. Maybe it could
save a life or a sexual abuse crime.
PS. I am sending this to everyone I know because I think it is
fantastic. Would also be useful for any emergency, such as a heart
attack, where you can't reach a phone. My Mom has suggested to my
Dad that he carry his car keys with him in case he falls outside and
she doesn't hear him... He can activate the car alarm and then
she'll know there's a problem..
Please pass this on even IF you've read it before.
It's a
reminder.