I posted this to the users' forum, but that was probably a mistake.
I'm copying it to here in the hope that it might be useful.
(from users' forum...
> some time ago there was a thread about changing the brush icon between
> showing the brush size and a precise crosshair. I can't seem to locate
> that thread, but if I remember rightly it was suggested that the
> change should happen at mouse-click, or when holding the mouse button
> Now I've just discovered, quite fortuitiously, that in photoshop (at
> least in Elements 2, so presumably also in PS7, on which the elements
> code was based) that you can toggle between these icons (i.e. brush
> outline vs. crosshair) using the caps-lock key.
> Maybe that might be a good idea for GIMP also?
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