geekzhang writes:
The University of Tokyo in Japan has developed an impressive Java applet program — Teddy, described as "a 3D free-form design sketch interface," which can automatically convert your 2D sketches into complete 3D shapes. Here's a 5-minute video:
Of course, you can go to the website and try it out directly at http://www-ui.is.s.u-tokyo.ac.jp/~takeo/teddy/teddy/teddy.html.