I found the following through the Procrastineering blog:
What you see here is Rhonda, a 3D modeling tool which makes use of freehand drawing for defining geometry. And I want it! I'm good at drawing, but can't get my head around 3D modeling. Well, I have done some architectural models, but I fail epicly with anything organic. Something like Rhonda seems like a way of getting around this problem by leveraging something which I do know how to do.
What the video doesn't show though, is whether you can go from these wireframe impressions to real solid geometry...