moira_ramsay just had an
interesting post about those questions mundane people ask whenever they see people in garb. Her reply was about the SCA, but I think it applies the same to Faire folk as well.
She also commented in her replies that she used to have business cards she would hand out to people to provide a bit of info about the SCA, and I think that is a wonderful idea. I plan on making up a set for ren-faire in my area, and for local SCA info as well.