BigClock: Current date and time displayed in huge letters. Supports four world time zones, four alarms, four timers/stopwatches. Silent, backlight, and custom tone alarms. Freeware.
BugMe: Pop-up yellow sticky notes for the PalmPilot. Shareware.
Cesium: Highly rated clock, stopwatch, and alarm software for the PalmPilot. [Shareware]
EarthTime: Graphically shows world time zones and their corresponding times. Shareware.
Game Timer: An application for the PalmPilot which takes the place of a mechanical game timer (such as a chess timer). Freeware (source available).
WorldMate from MobiMate: A collection of Palm travel software for world travelers. Features world clocks, auto-DST, and currency and clothing size converters.