What is the best lock?

TheBrick Don't leave it out side overnight reguarly it will be nicked. If the halls are really that arsey get your self a bike bag (one with out padding is cheap £30) and put it in there. Or just "Hide it" under a sheet in your room. As long as you are descreate, cearful about chipping paint on door ways leaving mud / oil everywhere e.t.c you should be o.k. If you are nice to your cleaners and keep your room ok other wise they will be cool. Bring your bike up after a week or two after you have sused out the situation. Only lock a real beater outside overnight reguarly that you don't mind being stolen.

The krypto chain can be broken in a 1 min or so check out the vid.

That's a good idea - I didn't think of a bag! I really want to ride whilst at uni - I think i'd go crazy without it :-|