The search for holy grail ;-) software is not over, but there is one flaw in the ocean of Mac software: gps and/or geocaching related software. I don’t say there is no software for Mac, but it is not as widespread as Windows software and some types of software aren’t just there (yet).
Magellan (who?) is forgetting about it totally (but about a lot of other things too!) at all and Garmin is starting to support Mac since a few months with different programs that are still in beta (BUT being worked on! :-D)
The most recent Mac OS X I did find (read: a few days ago) is GeoJournal. A program that makes it a lot easier to get you geocaching waypoints and cache info to your devices.
It can make the (by geocaching.com) delivered waypoints from GPX to Garmin, Magellan, Lowrance or even TomTom Navigator 5.x and can export to CacheMate, that is available for Palm for years and years now, and for Windows Mobile about 1 year I say from memory.
For Mac users that are into geocaching GeoJournal is for sure worth the try.apple, geocaching, gps, gps games, mac, os x, treasure hunt