I think the best reaction i ever got wasn't from a stranger but one of my university lecturers. After a 'play around' (an informal aikido session with a few fellow aikidoka) I has to go straight into his lecture (complete with weapons) since they were in a bag i thought i could escape, expecting him to make the same mistake as most and view them as a pool cue. no sooner had i sat down (almost bowing on my way in) than i knew i was busted, because the title of the criminology lecture was 'armed youth' (AAAAARRRRRGGGHHHH
SO i tried to keep my head down and get on with the lecture, half way through the lecturer liked to give us a break to stop the concentration levels dropping, after this we all came back in only for me to be asked what was in the bag by the lecturer, after MUCH persuasion and failed bluffing the truth came out, that pretty much spelled the end, for the next 10 mins i was stood on my chair showing some 200 people the array of weapons i had with me at the time (thankfully i hadn't brought my 'live blades' with me or we would never have got back to the lecture.
Obviously after the lecture all the guys i sat with were desperate to have a try of some of the weapons, my reply.......... "come to the class"