After much deliberation on tools over many months I have added Scapple to my collection. Made by Literature and Latte (of Scrivener fame) it is a free form note taken tool that can support brainstorming. I will be using it to explore some ideas and will write up my experiences.
While I do that I would be interested to know what tools other people use for thinking about projects apart from pens and a sheet of A3!
I found an interesting blog called Writing While the Rice Boils which has a few posts including some on tools. One of these mentioned Scapple which reminded me to pick up a copy. I will keep an eye on the blog (it went dormant last year though the owner has posted in March 2014) as it looks like it may well have some interesting insight to offer.