Achieving traced image effect?

Does anyone know how to create a traced image effect like the flowers in the first few images at this page http://www.electricheat.org/ ?

I have several techniques I use in photoshop (Poster Edges, Find Edges, etc) but none of them achieve such a clean look. Outside of tracing the images of flowers by hand in Illustrator, is there any other way to get this effect?

Thanks much,
Haig