Michael,

Section views can be useful both for presentation and to help understanding the shape one is working on.
Here is a this plug-in for Rhino, made by Asuni-Cad.
I think the way it can use a 3d clipping object for showing the internals objects to be intuitive and easy to use.

http://www.asuni.com/?category_name=labs

-Fredrik

Hi Fredrik - yeah a clipping plane type mechanism is a little different than a section command though.

A section command would generate curves - see for example the Rhino "section" command rather than that Asuni plug-in.

But you should be able to get the exact same result as a section curve generation command with MoI's current Project command, just draw a line and use Project.

- Michael