Circle3P.py
put a circle on any mesh using 3 verts. Add the script to your "run script folder" and it asks how many sides you want. You get a perfect circle on your mesh that is independent of the original mesh, the rest is up to you !
CatenaryCable.py
If you have ever wanted to add cables to your model it can be tedious. This script does the work for you using verts as the connecting points.
Would really like to mention the person who created these but the site is in Japanese.
You can download them here:
https://www.dropbox.com/s/22zm1bvbrnqsz5f/scripts.zip
Cheers