I make it a point to play "Spot the CCW" when I'm out and about. It's one way to keep yourself alert to your surroundings at all times.
Obvious ones are the vests and ManPacks. One guy was carrying a fanny pack with a fixed blade knife, tactical ring flashlight, and mace all attached on the outside. One other time I saw a man wearing the fishing or tactical vest (your choice of words), but unfortunately the vest was A) too tight and B) buttoned up around his gut and his fullsized something-or-another was printing beautifully.
Here in Reno, I spot a person I believe to be armed about once a week. I'm usually only out on the weekends, but it's fairly random when I spot one. Shopping mall, grocery, movie theater, etc. they're all around up here.
Rock out with your Glock out!