Audioguru, I think you misunderstood what he was asking for.
He's looking for something like a keyfinder circuit. Where you have a small button cell powered receiver with a piezo speaker/buzzer and when you push a button on a transmitter board the reciever board sounds a moderately loud beep or buzz which persists until it is canceled by a second transmitter or a reset button on the receiver.
I've been thinking of making a pair of these for my fiance who always looses her keys, but I havent bothered to sit down and figure out the power requirements. I think that it may be difficult to make it last long enough on a single battery, but I could be wrong.