I don't see where apple2gs wrote that he locked his bike. My opinion is quick stops are the most vunerable situation because you think it's safe because you're away only a moment. Why spend more time setting up heavy duty locks than you will be in the store? With a "grab and dash", it will take only a minute for a thief to be completely out of sight. That's why I have an extra light duty lock already attached to the frame and takes just seconds to attach to anything big and heavy, like a newspaper rack. It's just to prevent a "grab and dash" theft. It seems to be the most common type of theft.

Best of luck getting your bike back. You might also try scouting around the area for a few days. Some times it's joy riding and they dump the bike somewhere later on.