Mind mapping is a useful way to organize your thoughts and ideas in a more logical and ordered way. PersonalBrain is one of the better applications out there for this kind of task, allowing you to map your ideas very fluidly as you think.
You can use PersonalBrain to create diagrams, networks or simply sketch out your thoughts. You start out with a 'Brain' (i.e. a thought), and then build it up into something more concrete. What makes PersonalBrain a bit better than many other similar apps is that you can even drag and drop files and web pages into the mind map to make it more useful and richer.
The functionality can be poor at times however. Because its based on Java, it can take while to startup and responsiveness can occasionally be slow. Surprisingly as well, PersonalBrain will only let you export your mind maps in HTML format, and it would have been nice to have a choice of other formats such as OPML, Powerpoint and RTF formats for more flexibility, such as that offered by EDraw Mindmap.
On the whole though, PersonalBrain is a very flexible mind mapping program which lets you write down and connect your thoughts very easily.
