At this year’s Hacking At Random event/conference (HAR2009), a member of SSDeV (the “Sportenthusiasts of Lockpicking”) managed to pull off a very cool stunt: he copied a key for police handcuffs without owning the original key itself.
What he did was print a key using a 3D printer; the key was created and checked by using high-resolution photographs taken at the conference. Police were wearing the keys for everyone to see, apparently unaware of the risks they were taking.
At the end of the conference, Ray was able to talk one of the police officers into trying his key; to their surprise, he was able to open their handcuffs. He has since posted the STL file used to print it so others can try to replicate his success. Blackbag.nl has more details and pictures from the event.