essential tools for high concept doco film making

Boy it is tough trying to think of everything when doing a film about concepts.
So i heard about mind maps and there is alot of software out there, some quite expensive.
Not only that they can be really confusing , and i mean too many options.
But i decided to look at the open source version and came across a couple.

http://freemind.sourceforge.net/wiki/index.php/Main_Page
this one is okay but the graphics look like they are from the early ninties.

http://cmap.ihmc.us/conceptmap.html

This one rocks for me. It's intuitive. I give it teh big thumbs up.
I have a mind map of my film in less than half and hour!!!