well i guess i am on the other side of the fence from everyone else.
i went to school in lubbock TX. i don't know where you are or where your college town is, but i ran a 3/8" cable lock with a normal masterlock padlock on it for 3 years with no worries and no troubles. it was a very low theft area, and it is not remotely near any high theft areas that might promote "commuting" out to the college town to prey on their stuff. there was no cutting of locks in lubbock. if you left your bike unlocked, someone would probably walk off with it, but no one was bothering to carry around bolt cutters to turn a profit or sell it for crack money.
when i moved to baltimore, i quickly replaced this with a krypo u-lock, but there was never a need to do it before.
the way i think of locks is that that if you want to keep your bike, the safest thing is to have a lock that is more difficult that the lock next to it. bike theft is predominately a crime of opportunity. look at all the bikes locked up around your campus... if they all have ****ty $10 locks, then get something better... but if a lot of them have nice U-locks, you should probably keep up. if someone comes looking to steal a bike and they see a 30-sec job and a 5-min job, they're taking the 30 sec one.
i'm also curious as to everyone's dismissal of buying a huge chain from somewhere like home depot? does anyone know the strength of those chains? as for the "if they cut it with bolt cutters in the shop..." comment, when i've seen those chains cut, it's with a hydraulic press, not ****in bolt cutters.