This was a fun interactive performance piece at the 'Being Modern' exhibition. Museum attendants, equipped with black pens, mark the height of visitors as they come through the gallery. By inscribing horizontal lines on the gallery walls, accompanied by each visitor's name and the date the measurement was taken, a collective, changing portrait emerges. It echoes the tradition of recording children's heights on the door frames.
Of course, I did participate in the 'portrait' and was amused to find my height was right in the centre of the emerging line ... a very average kind of girl!
I like the idea. I once visited an interactive art display at the Baltic centre in Newcastle. There were huge mirors reflecting the coloured light coming from the ceiling panels which we could interact with. it was great fun. Think it was a French artist but can't remember his name.