Is it a wheel style (masterlock) Left/Right/Left deal, or, is it a 3-4digit barrel type?
You can try all the combo's for a barrel type (10,000 can probably be run through in a few hours sitting and watching TV).
If it's a master-type lock, there is a way to 'pick' them, but, I never got good at it (took me a few hours in a quiet area). It takes a good ear and a lot of patience to figure it out. Is it worth trying instead of buying a new lock? Doubtful. Is it worth trying if you're bored and curious... maybe.
A google search revealed a few how-to's. Try 'how to pick masterlock' and keep an eye out for textfiles.