"Unpickable" bike lock
digg.com
digg.com
Ten years ago, Kryptonite made a bike lock that could be picked with a Bic pen. They've changed their design, but a lot of locks are still on the street that can be easily picked, and criminals know exactly which locks can and can't be picked. The benefit of picking a lock is that the act of picking a lock and using a key to open a lock can look very similar to people walking by.
But there are two points which suck: it takes about three to four times the time to open than a normal bike lock - and the key is not able to be attached to a keyring etc. and thus prone to fall down on the street or worse, into a water relief hole and no way to get it.
Kryptonite claims with their New York Fahgettaboudit that there are deadbolts on each side, because typically - one cut of the shackle and you can spin the bulk of the lock out of the way. A lock manufacture basically confirming the shackle is the point of attack in a lot of cases.