Security guards are a real mixed bag... At my work there are a few real jerks. They just seem to cause trouble everywhere they go, hassling people they know for IDs, enforcing random rules at random times, etc. Those are the people with no skills who's family said, "Hey, you are a real jerk, and you have no regard for people's feelings. You'd make a GREAT security guard!"
Then there are the cool ones, who know its a job, and who follow the spirit of it all, instead of just the minutea. When I walk in first thing in the morning this one guy always has the door open for me by the time I get there, with a "Yo Sam, how's it hangin'?" But its not that he's lax, if random folk come up, he finds out what they need, and won't let unauthorized people pass, its just that once he knows someone, he knows em, and shouts friendly stuff at them when he sees them. And its not the pay or hours thing either, because he works the crappy super early and super late shifts, and gets paid the same as everyone else. He just happens to not be a jerk.
Oh well, I like the idea of the "Smile, I'm Not A Messenger!" button, its totally ironi-chic. I bet some messengers would wear them if you made them.
peace,
sam