I just got miauu's Work Plane. It's a maxscript utility to set working planes easily and to automate a working plane to appear in your viewport on the major X,Y,Z axis that is closest to perpendicular from your current viewport. It is convenient for working in the perspective viewport. It also has other tools for seting working planes and reusing them.
I really love the tool. It's costs 10 Euros (about $13). Well worth it. If you get it from this recommendation... let 'em know Wall Worm sent you.
miauu's Work Plane on Scriptspot (http://www.scriptspot.com/3ds-max/scripts/miauus-work-plane)
miauu's Work Plane Official Web Page (http://miauumaxscript.blogspot.com/p/commercial-scripts.html)
That would be handy for creating a mesh on a convexity wall or helping out with creating your props :) hmm I might get this :)
Version 1.07 is now out. Check the credits in the 1.07 help file. You'll see a familiar name! :)
The new version has several new little enhancements. If you don't have it, you should really get it! A+... two thumbs up!
A new version compatible with 2013 is now out. This is a MUST HAVE script for all WW/Convexity level designers!