Interaction without technology

Measuring the Universe (2007) is a nice example of a piece of art which claims to be created by its audience, yet it is not technologically interactive.

“… is a performance-based work in which the height of each visitor is recorded on the gallery’s wall by a Museum attendant, eventually creating a unique wall drawing and a visual record of thousands of museum visitors.”

http://www.moma.org/visit/calendar/exhibitions/980