I also just found this: Ace Breaker kit
Pretty tough stuff!! Might be an overkill for your problem - you might find you can just hammer a screwdriver into it and turn it with a pair of stilsons, but I guess that might damage more than the lock.
My grandad did locksmithing as part of his builders business - my nan has a large bag full of various keys (including some monsters!) and a full set of lever-type skeleton keys which seem to work on quite a few modern locks! There are also lots of bits of wire with hooks bent at angles but I haven't really tried to use them.
It is something that would be pretty neat to get skilled at - these days most solutions for people locked out is to bust the door or window and replace whatever breaks. I expect there is a shortage of "real" locksmiths.
One booming market in the UK would be wheel clamps - there is a guy in Portsmouth who can pick wheelclamp locks in five minutes and charges £40 - to have an unskilled monkey use a key is £99!
edit: I can't help but include these pics taken in Portsmouth of the clampers that the above locksmith is targetting:
Gareth