Finding the various r-map threads months ago inspired me to find a mind-map tool for which should also be really useful as a relationship map tool.
A number of the suggestions in the threads were interesting but didn't do it for me completely for various reasons. My requirements were:
1. It had to be easy to use and intuitive: I didn't want the process of using the program to get in the way of my ideas. If that meant sacrificing options for the sake of simplicity and ease of use, so be it.
2. I wanted it to be local, not a tool I can only use while connected to the web.
3. The data needs to be exportable; I didn't want my data locked into a proprietary format only usable by the origination program.
4. Mac OS X compatible. You can take my Mac Book Pro out of my cold, dead hands.
5. It should be low-cost or free. I don't mind paying for software but I can't really justify paying $100+ for a program I know I wouldn't use a lot.
I found C-Map which is far from perfect but excellent in other ways and certainly fulfills my five requirements. (and, yep, it's free)
Link here: http://cmap.ihmc.us/
I hope this helps anyone looking for a similar product.