Brainstorming is part of the processes to generate new ideas. Bubbl.us is a simple and free web application that lets you brainstorm online.

http://www.youtube.com/watch?v=AllXU_3nktU

With Bubbl.us, you can create little thought bubbles and connect them together. You also can easily move the bubbles around or change the links connecting them to each other. In a nutshell, Bubbl.us is a simple “mind mapping” online application. Even though there is not collaboration feature, but it’s free and it’s fun, and it might help you see connections in your own thoughts.