I want to note some of the useful tools that I find here.
Top of the list is FreeMind, an open source mind-mapper. I am using it almost every time I want to take some notes or record and organise some ideas. I use it for my “to do list” and for planning various projects.
The real test for me: I am using it instead of grabbing a piece of scrap paper.
It uses Java so it runs equally well on Windows and Linux.