A very cool book! I was exposed to mind-mapping by Ed Young, pastor out of Texas. I have been using it for about a year to help me prepare and deliver sermons and it is a great tool! It uses the premise of free-association to help prepare and organize various thoughts about a subject. It saves time, emphasizes key words, and emphasizes new discoveries than linear notes would allow you to do.
It's much more complicated than what I can put in a blog and I'm sure I don't have it all down yet. But, mind-mapping has helped me to take a mental "picture" of any presentation and sermon and deliver key thoughts, images and stories without stumbling over a linear 5 page written essary.
If you're curious about mind-mapping, check out these links below:
http://en.wikipedia.org/wiki/Mind_map
http://www.youtube.com/watch?v=MlabrWv25qQ
