I always have my camera with me. If there are people around, I pretend I am taking closeup pictures. Macro photography always necessitates getting into odd positions, as does hunting for a microcache.
Other people incorporate an orange vest and a clipboard as a way of looking official and therefore less prone to scrutiny. Someone who looks official will not merit a second glance in comparison to a single person just milling around, seemingly without purpose.
Anything you can incorporate into your "outfit" so you do not become an object of either suspicion or curiousity is a good thing.