Is that a cylinder lock? Like they use in vending machines?
Not a replacement, but many of those can be picked with the tube of a Bic pen (http://www.wired.com/culture/lifesty.../2004/09/64987
) or do a web search for "Kryptonite + lock +Bic"; should yield a bunch of results.
I would hazard a guess that a locksmith could probably make a replacement key (or keys), but you would probably have to remove the lock and take it to him. Most likely will be kind of pricey as well (specialized labor, you know...)