Few years ago I implemented the basic function of Takeo Igarashi's "Teddy" in Matlab, which converts a 2D closed curve to a 3D object. That was meant to be a practice, and also for possible use of streamlining few of my own applications.

Last year I build a 3D printer, and now I have a good application to use my implementation: turning hand-drawn doodles to real 3D objects! The whole process is automatic with minimum manual intervention (the extraction of silhouette, which may as well be automated by some basic machine vision techniques).