Another Add-in Challenge = determine Wall orientation relative to North and add to Parameter

I received this request via email:
a question in revit vasari or you can get the orientation and exposure of a face of a mass or a wall
for example classify all the walls to the north or the south-west?
and put them in a schedule of the walls?

Vanilla Revit can't do this. But perhaps someone would like to make a little add-in, macro or script that processes Walls, determines their 'facing' orientation, and then inputs this data into a Shared Parameter of Walls? Successful challenger will obviously get a mention on the blog.

Maybe something like this already exists out there... Feel free to comment!

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ANSWER
Thanks to Amy Manning, who 'reminded' me that Case do have a tool that does exactly that :-)

@lukeyjohnson doesn't case have one like this? It reports either the orientation or the angle of the wall and writes it to a parameter.
— Amy Manning (@amyonymous) May 17, 2013

Its the aptly named "External Wall Facings".  More info at this link.

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Much of the legwork was done back in this 2010 post by Jeremy:
The Building Coder: South Facing Walls

Note:  I used my Revit Master Search, which led me to this post, which led me to Sort and Mark by tools4revit.  However, I don't think this adds orientation relative to North - I'm pretty sure it just determines Flip/Mirror orentation?