Many additional applications can be loaded into the free memory of a Palm organiser.  In fact there is an enormous number and range of third party applications available.  These can be easily found in one of the internet PalmPilot software depositories.  Most are free or can be purchased on-line for a small price.

The following are some of my favourites :

StarPilot - choose location, turn on backlight & look up !
 

BibleReader - readable, searchable & in many versions.
 

Space Invaders, Galaxians, 2-Player Tennis, Chess etc. !