I have an on going photography project with my old outfit. The basic idea is that I follow them around and post photos for the outfit's Facebook page for the current cadet parents, starting in a few weeks I'll be in my third year of working the project. By working I mean I'm donating my time and effort and I will say that it has been an incredible experience, making me feel both young and old at the same time as I have had the chance to get to know the current cadets.
It is very special to me that the current cadets let me come follow them around to photograph them, they don't understand why yet, but give them a decade or more past second pass and they'll understand!
http://oldarmyc.f8industries.net/main/