I use it for that, also to find out where my car is in a car park.
Confuses soooo many people though. The amount of times we've had people chase after us saying "You've left your lights on!"
They get so confused when I say "No I haven't..." and they turn to point and they've gone out....
Makes me feel a little guilty, but I generally just say "yeah, they do that." and it's okay
Also a great deterrent when there's chavs hanging around your car. Many a time I've had fun clicking the button when sitting in a restaurant or in the lobby of a shop or something and they've jumped like mad and ran around the car staring at it.