>For example, you have two inspectors open and you want to see if they're
>looking at the same object.

You could compare the hash values of the inspected objects:
Evalute "self hash" or "self identityHash" in both inspectors
to see if they inspect the same object.
(self refers to the inspected object in the code pane of an 
inspector, not the inspector itself)

Bye
Torsten