[EDIT: Moved from Beginner Lockpicking Questions to Questions from the Public - This Old Lock]
D&D makes gate locks, for what looks like the Australian market. Do you have a backyard gate or a fence around a pool that has a locking gate?
I just used Google Image search, looked for "D&D key" and found out what it went to.
Look for this kind of child safety device on your pool fence, the key goes up into a keyhole you probably wont even notice:
http://www.amazon.com/Pool-Safety-Gate- ... y_86_img_ya 4 pack of your keys if you need more.
http://www.amazon.com/Magna-Latch-Repla ... 00K22AAAG/hope this helps!
Squelchtone