Greg -

>    Is there any way currently built into Squeak to 
>search for any usage of an instance variable without 
>doing a full-text search?

You bet.

>The menu's contain
>"references to it", but when I choose a variable
>and select "references to it" Squeak never finds anything.

This is not what you want.  In the full browser, browse to a class, and invoke 'inst var refs...' in the class pane.  This will give you a menu of all the instance variables and, when you select one, it will put up a browser on all methods that refer to that variable (up and down the superclass chain).  You can also choose 'inst var defs...' if you want only those methods that store into the variable.

These commands are available in many of the other browsers as well, in which case they are interpreted relative to the class of the method currently selected.

Hope this helps.

	- Dan