Blender Tip for Skeinforge Users:

Blender seems to add a lot of vertices whenever you import an STL file.

This doesn’t happen on export, or if it does it hasn’t bothered Skeinforge, but I’ve had meshes fail to slice in Skeinforge because of the vertices that got added when I imported to Blender, resized, and then exported without removing them.  The first thing you should do after importing an STL in Blender is to go to edit mode, select all, then select “remove doubles” from the vertices submenu.