COINS Auto-Section Box

The COINS Auto-Section Box tool gives you tremendous speed and agility over managing three-dimensional views when analyzing model areas of particular interest. It allows you to quickly create temporary and permanent views to be used for immediate interrogation of the model or for construction document deliverables. This works by allowing you to focus on the model instead of managing views or a view’s properties.

There's a tutorial-like writeup on the COINS  Auto-Section Box tool on David Light's Revit blog.

This free add-in can be downloaded from the Autodesk Exchange | Apps website.