xD We don't really have hidden keys. They expect me to know where the key is, and I'm not fool enough to call them if I do lose it. Rather locked out searching day and night than dead for complete lack of irresponsibility. But once, my mom put it in a plastic bag that was in the huge, folded umbrella. Another time, she hid it in a shoe. o_o; Mom can get really creative about this.

I have spare keys all over the place.
Mostly cause I'm scared I'll lose one, but I always know where there's another.
For the house/car I have them in my wallet/purse. I have an extra house key in the car, in the garage in a box of my books between the pages. Buried under a little cross. >.<
For my car I have pretty much only the one in my wallet...
I need to put more other places.
lol.

hmmm...i think maybe in my bbq ^^ that would be an okay place...might be difficult to find...but my family and one of my friends has keys to my house just in case so i dont really ahve to worry about that.