Sato Hiroyuki offers some useful scripts for Adobe Illustrator.
Adjust Dashes script
Particularly handy are Common Tangents which creates paths between tangents of the selected objects, and Adjust Dashes which fixes glaring shortcomings of dashed strokes (above).
Hiroyuki posts scripting experiments on his blog.
Awesome! That adjust dashes script will be very useful for me.
I use Common Tangents pretty frequently to join ellipses to make cylinders in isometric or perspective. Select two or more ellipses, File > Scripts > Common Tangents.
Sometimes connects tangents on opposite sides as well, you can just delete them, but beats trying to find the exact tangent yourself.
Amazing!