BeltedGirls.com

I think it is mythology when people say the key is broken and the lock on their belt means they cant get out of it.My key is broken in the lock,it was no accident Guess what? I can still lock and unlock it,no real problem there.A little bit of jiggling with remainder of the key inside the cylinder and it works fine.There is a proviso though, the sting in the tail of the scorpion!You MUST use the remnant of the broken key to unlock it!If you cant, yes your in trouble, it wont unlock with any old key.You cant even pick, you cant get into the cylinder at all.I hear there are ways of extracting broken keys?I wonder what they are.
Short of cutting the belt off, I think my junk belt is virtually escape proof, its all riveted.If you don't have that key................

Lizza

Actually, I should not give this advice, women should wear their chastity belts and not try to get them off.
Promise to only use this in real emergency!
7 tricks to get broken key out yourself - any lock or key
http://www.youtube.com/watch?v=63tQH1DIqIw

They make key extractors, Lizza.

They look like super slim saw toothed shims that you slip in on the keyway ridge side and it grips into the soft brass of the key.

I have used a ground down scroll saw blade before, but that was on a very large padlock with a monster sized keyway. A small padlock would need a very thin key extractor.

another way is to use some quick set epoxy on the tip of the broken key. Stick it back in and glue the broke piece back on. (sometimes this works, like 10% chance) lube lock very good with dry graphite first. pull straight out, no wiggle!

I've had good luck removing small keys from small locks with a slightly modified dental pick. I use the straight side, and bend the very tip just a hair, and stick it in so hopefully I can catch it on a part of the key body and wiggle it out that way. Sometimes it works from one side better than the other, depending on the key.

For padlock style locks, I just use a bolt cutter and buy a new lock because that's easier.

A broken screw extractor bit can also be used

a broken screw extractor can also work.
Drill a small hole in the back of the key and glue the drill bit in place to make a handle
You can heat a brass lock with a steel key and the different expansion rates might get you enough wiggle room to get the key
If you don't mind destroying the lock you can just drill the cylinder.