Inspectors menu
Show/Hide Inspectors — Summon up the inspector window, or put it away.
Reset Inspector Locations — This is just in case your inspector window somehow ends up in a weird offscreen location and you need to get it back.
Action, Group, Project, Context — Switch to the corresponding section of the inspector window. You may never need to do this, as the inspector does a pretty good job of automatically switching to the right section as you select things.