NURBS Modeling
Read/write 3DM file; Copy & Paste geometry via clipboard!
http://www.rhino3d.com

3D Mechanical CAD
Read/write 3DM file
http://www.spaceclaim.com

Generates unfolded patterns from a (low-poly) meshes
Read OBJ file (also LWO, 3DS, binary STL)
http://tamasoft.co.jp/pepakura_designer/

Flattening a triangle meshes to 2D patterns
Read OBJ, 3DS, STL file
http://www.laminadesign.com/

Converts bitmap to heightfield surface
Write IGES file
Download link (zip 0.5 MB)

Program which creates a relief type surface from an input bitmap, where height is controlled by the brightness of the image.

MoI forum