The furniture designer in me loves this idea.

open-source software that takes a sketch of a chair design and turns it into a set of files that can use a Computer controlled router and make your design.

or run it on a craft-robo knife cutter and make a model, make loads of models!

http://www.sketchchair.cc/

Watch a video

http://vimeo.com/diatom/sketchchair-kickstarter