Germany Pavilion, EXPO 2015 (Rho Fiera), Milan (2015/08/05 13:38:25+02:00)
They gave everyone a board with special markers and if you hold it over the tables video is projected onto (and it knows what language to display from the pattern of the markers). The projector follows the board of you move slightly and you can tilt the board to select chapters and stuff (I want one of those projectors).