From Aaron Koblin's TED presentation:

"Artist Aaron Koblin takes vast amounts of data -- and at times vast numbers of people -- and weaves them into stunning visualizations. From elegant lines tracing airline flights to landscapes of cell phone data, from a Johnny Cash video assembled from crowd-sourced drawings to the "Wilderness Downtown" video that customizes for the user, his works brilliantly explore how modern technology can make us more human."

Beautiful, incredibly creative use of user contributed hands for data-driven art.

http://www.ted.com/talks/aaron_koblin.html