This was an interesting concept of using a projection onto a 3D object to carve it to the right shape.
http://www.newscientist.com/blogs/nstv/art/
http://www.alecrivers.com/sculptingbynumbers/
http://www.alecrivers.com/sculptingbynumbers/files/Sculpting%20by%20Numbers.pdf
A failry low-tech idea of using the traditional use of kite flying to monitor air quality.