Clement Valla created an online tool with one function: users could trace lines. Each user sees only the previous line, and is instructed to trace it as precisely as possible. Then it’s passed down a line of users, each tracing over and over. You’d be surprised how nutso this “straight line” thing gets after several hundred tracings.
In the video below, Valla’s “A Sequence of Lines Consecutively Traced by Five Hundred Individuals” starts slowly, then speeds up, so you can see the line grow and change across its lifetime. Valla paid users of Amazon’s Mechanical Turk system $0.02 each to trace each line, then assembled the video. I’d love to see what a more complex form (like drawing a face, then tracing it 500 times) would look like.