GeoToad
I discovered GeoToad this weekend. I haven’t messed with too much, but I already like it.
It’s written in Ruby, so it will run everywhere natively (i.e without Cygwin or a Unix environment). I’ve been having problems with the geo-* tools that I have raved about before. They assume that you are using GNU tools and the BSD utils that come with OSX behave differently than their GNU counterparts — different command line options, etc. So I needed something else. GeoToad will fit the bill.
I don’t use the full-screen interface — that’s for wimps. 
Instead I’ve been using the command-line interface. Both of them do the same thing. One of the great things about GeoToad is that it caches it’s results. This prevents you from hitting Gecaching.com over and over again. They get picky about that. GeoToad also exports GPX files with the the groundspeak namespace. Doing that with the geo tools took a lot of time, but GoeToad does with by default, and with ease.
I’m looking forward to hooking GeoToad up with GPSBabel and having a good ol’ time with hacking with geocaching data.
Let me know if you figure out how to launch GeoToad from Quicksilver. I can’t get it to work.