Sounds like you have a nice mail carrier. The one we have just scowls when you walk by and try to say hello.
I wear my DIS Unplugged shirt quite a bit (usually when I'm out walking) and keep thinking someone is bound to notice it and mention they are listeners as well. I even wore it when we were at the Daytona 500 back in February because I knew there were some people from the boards going...but no luck. Oh well, one of these days!