I am now a contributing editor of Technical documentation for the CHIRP project. CHIRP is a free, open-source tool for programming your ham radio. It supports a large number of manufacturers and models, as well as provides a way to interface with multiple data sources and formats. With CHIRP you can easily upload or download frequency settings to/from your supported ham radio. Many people report difficulty even remembering how to program this sort of info into their ham radios by hand, and many ham radios have hundreds of memories. CHIRP makes it easy, and also allows you to save a backup of all those settings, or even transfer your favorite stations from one amateur radio to another.
CHIRP is a Python project, and it runs under Mac OS X, Windows & Linux.
I started with the “Mac OS Tips” documentation.