If anyone lives in Sydney this hunt might be of interest to you:
Monorail Treasure Hunt

It is a Monorail treasure hunt round Sydney that opened on 1st May 09 and closes on 31st July 09.

By the looks of it you have to purchase a ticket to travel on the Monorail and get a Treasure map. Then follow the instructions on the hunt website at Monorail Treasure Hunt

Prizes include a family holiday, experience days and toys.

Good luck if you are entering