the legend of the purple hat
I'm a regular at PyCon US, and recognizable in a crowd with my distinctive purple-and-white striped hat. It's a way for attendees to find a welcoming smile and ask any questions they might have, without the solemnity of finding some (other) official representative.
(Not just for those who know me -- I've announced it to audiences in my capacity as an organizer, and in fact the practice originated a few years ago with the core organizing team. I've just kept it up!)