Bicycle Mechanics - Mongoose bike lock help

My key sheared off inside of my bike lock today. I have another key, but the bottom half of the broken one is stuck inside of the lock. I've tried repeatedly to remove it, but to no avail. Do you have any recommendations on how to get the key out? I need the bike to get to my classes on time. Unfortunately, the only solution I could find is asking the sculpture professor to take a blow torch to it. Does anyone have a suggestion other than destroying the lock?

The bike lock looks like this:
http://upload.wikimedia.org/wikipedia/commons/7/79/Fahrrad-buegelschlosz.jpg
Not the right brand, but the shape is the same.

You could pay a locksmith to remove it, but that'd likely cost more than a new lock.

Try compressed air or a bobby pin?

if you can see the end of the key that is stuck in the lock try this, I've done it a couple of times on locks with good results. what you'll need- Paperclip, small coffee stir straw and some quick set epoxy. Cut the straw just long enough to stick out of the key hole a 1/4 in or so when pressed down to the key inside.( this is to keep the epoxy from sticking to the inside of the lock cylinder and just to the key. Now put a dab of epoxy on the end of the paperclip and maybe a bit into the straw if possible. Stick the paper clip into the straw untill it contacts the key frag and let it set up. should be able to pull the key out

if you can see the end of the key that is stuck in the lock try this, I've done it a couple of times on locks with good results. what you'll need- Paperclip, small coffee stir straw and some quick set epoxy. Cut the straw just long enough to stick out of the key hole a 1/4 in or so when pressed down to the key inside.( this is to keep the epoxy from sticking to the inside of the lock cylinder and just to the key. Now put a dab of epoxy on the end of the paperclip and maybe a bit into the straw if possible. Stick the paper clip into the straw untill it contacts the key frag and let it set up. should be able to pull the key out

Very neat idea. I wonder if doing the same thing but using superglue would accomplish the same thing but faster.

Thanks for the tips, everyone. I managed to remove it with some very small pliers.