This thread made me wonder about tripping in public, so I decided to dose 810ug of 25i-NBOMe at some electronic music event (a lot of Grime, Trap and the like, not really your standard tripping event) in Amsterdam as some substitution for MDMA which I couldn't get to in time. Didn't tell my friends I dosed up and even THEY couldn't tell I was tripping. To put this into a bit more context, there was an amazing form of patterning and fractals and kaleidoscoping going on and above the stage. All the while everyone's movements produced some weird "movement" type visuals I also have when I look at the plants in my living room while dosed up. I was dancing like I've never done before, while looking at my surroundings in complete awe. Probably had the biggest grin up my kisser too. During this I thought everyone was looking at me and found me weird, but in retrospect I wouldn't think so as at least 40% of the people were clearly rolling. (meaning: there were people doing weirder things every 5 minutes)
Also worth noting is that I had the feeling that my friends did know, and were whistling about it behind my back all the time, talking about how weird I was acting and such. They didn't.