Mindmeister

I came across this about 6 months ago and then, not being much predisposed to mind maps, forgot all about it. Then someone "discovered" it for me again a few days ago.

If you like mind maps and you’d like to construct a collaborative mind map online then check out Mindmeister.

Their basic account is free and allows you to have up to 6 mind maps at a time. This mind mapping software is simple but very intuitive and being able to work collaborate with others is a real bonus.