One of the tools that I absolutely cannot live without at work is Freemind, the open source mind mapping tool.
In my previous workplace, I was only assigned a desktop, so I was unable to utilise Freemind fully. Now when I have my own notebook, I have unleashed the full usefulness of the tool: organising my thoughts, note-taking during meetings, etc.
Why don’t you try it out for yourself? It’s really easy to use and before long you’ll also find it indisposable. Go to http://sourceforge.net/projects/freemind/ to download a copy and try it out yourself!