Is there a way to have AppleScript output displayed in the menubar? Before reading further:
I know about butler and similar programs.  I am looking for a BUILT-IN way to do this without a third party app.

Anyway, I wrote an AppleScript that runs a shell command.  I want to display that output in the menubar at the top... without Butler how can I do this?
As a generality, without a third party program, such as Growl, there is no built in way to do this.

However, you could write a script or other program such as one I found here that provides the menulet service for you.  I'm sure that Growl integration would be much easier to accomplish.