Being that I am not really a shy individual, I haven't had a problem with stepping up to any military or public safety personnel to tell them THANKS for the service they are performing. However, if you are somewhat reluctant to walk up to a stranger and share that feeling, maybe you should visit http://gratitudecampaign.org/
I have embedded one of their videos below (hosted by YouTube) for your viewing pleasure:
I am an ex-cop turned geek - which explains why I never have my back to the door and always keep one eye on the computer. I work for Oklahoma State University and am one of the primary "Go To" guys in the IT department (that is a couple of blog posts worth of info in itself). My official title is Manager of Special Projects, but that doesn't slow down the assignments given to me. At times, I feel like my title should be Manager of ODAA (Other Duties As Assigned)!