Here is an animation I made with Phun.
Quite hard to do, because I know the lock but not the software

and it's only 2D, so hard to represent accuratly the working of the lock, but the main principle is there.
This feature is implemented in several patented keys like those made by DOM for example.
http://www.youtube.com/watch?v=WGolAPIRFkE
Thanks for viewing,
Have Phun
FrenchKey