Mind maps are useful things to learn about. I first discovered them while I was at college. I picked a subject matter to test them on - the only notes I took were mind maps which I used for assignments and revision. I scored something like 96% in the final exam! (The topic was Operating Systems - not how to install them, but how they work under the hood).
I use them quite a lot for documenting ideas and things, and I bought a book on the subject especially designed for kids, so they can get into them too.
How can mind maps be useful in martial arts? Mind maps are organic and creative things which help you organise your thoughts very quickly. New structures and patterns emerge from looking at the pictures. I'm sure you can think of good ideas already!
You could mindmap everything from karate history to your personal training routine to the club syllabus. Or how about using them to document your research and training into different kata, including key applications? Make your own "Bunkai Map" and use it to share your ideas.
Mind mapping software is available for computers. One of my favourites is Freemind (which is free!) Freemind is a Java program which runs nicely on windows, mac and linux. Here's the link: http://freemind.sourceforge.net/wiki/index.php/Main_Page It's a very easy application to use.
Of course now I'm going to have to do a "martial mind map" or two and post them. Looks like I just got myself a little task to complete! Freemind allows maps to be exported in a whole range of formats, so watch this space.