Unfortunately, that's one of the things that kind of is a tad lacking in the MacOS X world. That and my GPS is an old one that uses a serial port to communicate with the computer, something you won't find on any modern Mac. USB -> RS232 port converters don't seem to work either.
I still use an old PC with XP to run the Garmin Mapsource (and Lowrance MapCreate for my aviation unit) and load waypoints, routes, etc. to and from the receiver.
However, I have found that Google Maps works well enough as far as locating where the coordinates are with any given location, which I then manually enter into the receiver to set the waypoint. Having it be a picture of the location is much better than just a standard Map. I do miss the ability to put in an address in DeLorme street atlas and have it reliably come up with the coordinates, but Google Maps seems to work just fine.
Someday I'll update to a newer GPS that has USB communication (or even bluetooth, which would be better) but the unit works just fine for now so why blow the expense?
