1) at the airline club (cloakroom). After notifying the staff fix the luggage rack in the cloakroom with your padlock.
2) clear your bag (s) of all airline tags, put your (home or next) address label on the outside and turn it in to lost and found. To make shure they don't ship it off somewhere, call them on the phone, identify the bag and say you will pick it up in an hour, or tomorrow, or whatever/whenever.
3) take the free shuttle to the next airport hotel, give a tip and store it there (try to look like you just checked out).
4) at the baggage-claim area, move your baggage to another (wrong) carrouseel, and claim your luggage as lost with your airline (this is especially helpful if you don't have enough space in your car and you don't need some of your luggage in the next 24 hours. The airline will probably forward the luggage to you).

(from the airline passenger's guerilla handbook, 1989, ISBN 0-924022-04-3, no longer available)