I saw this UI in Mozilla Labs for Firefox. It's still a concept and prototype for Bookmark and History/Time tracking... but I think it may be applicable (as an UI) to other apps including CAD/MoI.

What I find interesting is, if applied to Layers: it scrolls left and right across the top; it can contained nested layers/objects (pulled down/vertically), it can be zoomed in/out... To better understand what I'm taking about, please refer to it here:
http://www.vimeo.com/1466664

Cheers,

- Diego -