I would like to have full access to my data in a project file TOC while having open the Layer Properties dialogue of any given feature dataset. For example, I find myself with the need to zoom in/out, toggle between layout/data view, turn off/on a feature dataset or the like while modifying symbology, labels or query definitions, et cetera.
Quite simply, open Layer Properties, pick up Zoom In tool, zoom in to area of interest.
Presently I am running 9.3.1; I am unaware of this feature in 10.