I managed to get it open again, grab the backup quarter from my shorts, move everything to another locker, and get it all locked up so I could take the broken lock with the key jammed in it out to the front desk.
The dumb part is that tons of the lockers are broken, with no lock at all, while others have the key in them, but the door is still locked shut. They probably figured when they installed those that they could make a little money and wouldn't have to worry about people leaving locks on overnight. I much prefer being able to bring my own lock, and am fine with a policy where locks left on overnight are cut off.
The people I really don't understand are the ones who leave their stuff laying around or in lockers without locking them up. I don't care how cheap your stuff is, it's definitely worth more than a quarter.