Rob,

> Is there a way to break out of accidental infinite loops while 
> developing/testing code?  I'm in this state now and I don't 
> want to shoot the process since I don't want to lose changes.

Your changes won't be lost. Once you've terminated Squeak, restart it.
Then get into the world menu, click on "changes..." and select "recently
logged changes..." the system will ask you how far to go back (you
should probably just take the first entry in the list) and it will show
you all the changes that you've made since then. Nothing is lost forever
... except, of course, the Cathedral of Chalesm ;-)

Cheers,
  - Andreas