I've been reading about mindmaps for some time now. Even though it sounded like yet another management-hype, the idea seemed alright. It's a way to organize your ideas or data in the same way as your brain would use them. Creating an image that will give you the overall idea with the necesarry detail where you need them.
It wasn't until I saw it into practise that I got around to using it. And I'm hooked. It really is a great way to organise your ideas into something you can use. It turns a heap of notes, documents and images into a single logical map.
It's probably useless at home (unless you have a very organized private life maybe) but if you have a job where you are constantly working on a million things, with a million more details it's the perfect solution.
Right now I'm using the Mind Manager tool from Mindjet, which is proprietary software. But I like it. I've tried the freemind tool as well which is also great, and free. But it lacks some features that keep me from prefering it.