Only noticed this the other day so thought I'd share.
Am pretty sure it wasn't there on the initial OS 10.3 install but with my current 10.3.9 if you go to System Preferences>International>Input Menu Tab you can click on "Keyboard Viewer" which is just like Keycaps from OS9. Once turned on it can be selected from the Flag icon top right.
:D
... there was the puzzle of why the sun came out during the day, instead of at night when the light would come in useful.
Terry Pratchet