Glass balls
I was in Bergen the other day with some time to spare so was wandering aimlessly and caught sight of the girl in the picture. I'm not a big city person so maybe this is old hat, but I haven't seen this as a street performance before although I have seen it on the tele once. The normal offerings in Bergen are a couple of silver "statues", a Bolivian pipe band and a whole load of musicians from various parts of the world. The idea of the glass ball is the illusion that it is floating in the air, the performer moves their hands around it and it stays still. The ball has quite a large mass and hence large inertia this combined with a low friction surface means that if the hands is moved under it it stays in one place. I'm not sure what this all has to do with love, peace and psychedelic music but she seemed to be doing good trade.
The guy in the video is considerably better than the Bergen girl but could do with a bit of music.