I'm a great believer in mind mapping and use it for all sorts of things. On the creative writing course I teach at the British Council, I show my participants how to mind map their ideas as a springboard into a piece of writing. (The best book that has been written about clustering is Gabriele Rico's Writing the Natural Way. Her website is here.).
Start with a word (can be quite random) in the centre of the cluster and then map out all the associations you can make with the word. When you have filled up your piece of paper, start writing from any point of the cluster, and you will find you have plenty of ideas.
I've just stumbled across an amazing piece of software called FreeMind which is a great help with this process, and best of all - it's free!
I had been meaning to get started on a piece to submit for MPH's Ke Sana-Sini travel stories collection and today decided to throw my ideas down using Freemind. It worked like a dream. I love the way I can move things around and edit it, and add new ideas to it as they occur to me. It really does free the mind.
You can see how far I've got with it so far if you click up the pic below ... but don't expect to make too much sense of my messy chain of thoughts.
Now kick me if I don't have a decent piece written soon.
Damyanti also blogged about using mind-maps for writing here.