Anti-static stuff like wrist bands are recomended ir just toutching metal stuff for a while will do too.
Just touching ground/metal every so often is a common misconception. I used to subscribe to it too.
In the last ESD training coarse I attended it was clearly demonstrated that only a few seconds after grounding oneself enough static could easy be generated to fry a transistor (or IC). The static was measured with a static field meter. I later played with one of these meters myself and strongly agree that just touching ground momentarily is not good enough. Also you don't have to touch for long to discharge (not a while like you stated, its almost instantaneous). But you can be back up to a pre-discharge level doing normal movement in seconds. So if you are not using a strap or holding your metal for the entire duration, then you might as well not worry at all.
