Many dimple locks can be picked with just some tension on the cylinder and a ball pick. The common cheap Bell brand lock at wal-mart or amazon [1] is easily picked like this. All you do is stick the ball pick in the back of the keyway, apply your tension, and wiggle the pick around the keyway as you pull it out. You might have to insert it a few times, but I've been able to reliably open one of those in about 10 seconds.

1: http://www.amazon.com/Bell-Sports-7015777-CATALYST-U-Lock/dp...