This is maybe a tool that is used widely (or not) but has proved invaluable for myself and our project team.
Visual Understanding Environment
It's a free resource and very easy to use. Looking back at some of the original maps that we used for project planning, they are absolutely huge, difficult to read and not as focused as they could be.
The tool has enabled us to focus on the elements of our programme that are important to its success eg. resources/tasks.