Bubbl.us is a site which provides users with an interactive and attractive interface with which to make brainstorm and organise your ideas online.
First of all, you start off with a central subject that you specify and then you work around it by diagramming words, ideas, and tasks that are related to it, through the use of linked text bubbles.
These colour-coded bubbles can be easily moved around and manipulated with your mouse as you develop your ideas. A simple registration process allows you to save and print multiple brainstorming sessions and come back to them later.
Bubbl.us is simple to use and provides a quick and clean interface to help you in your brainstorming and planning. A useful addition to the toolbox.