Here are two quick families I made over lunch that I thought of on the bus. I have no idea to whom they would be useful to, unless someone is using Revit to lay out Egyptian temples or Neo-Classical Greek Plaster details; but anyways- here are two 'overlays', one for the Golden Section, the other for the Fibonacci number series.
They are parametric, and made up of 2D lines within a generic model family. You can drop one into your project, tell it the 'base' length, and it will auto-calc (and draw) 2D guidelines for the next few steps up in the series. Then you can snap anything you are drawing/modeling to it. Bam! Instant Greek Temple plan!
Anyways, have fun.