I stumbled over this tool and I am really happy with it. I am german - so I have to adopt to the missing language flexibility - but the offered way of organizing my thoughts, linking my files and data into this "brain model" is the kind of way to work on a computer I always was looking for. For me it is the next step beyond mindmapping or concept maps which I used until now.
Great Idea and great tool!!!
It is not really cheap, but you still get something useful in the free version.