eDraw Mind Mapping is a vector-based mind mapping software with templates for brain-storming, project timelines, life planning, SWOT analysis and Sketch Maps. Free mind map software (Freeware,requires download)
Freemind: another open source (so free) gem. Once you learn to make notes in a mind map format you can never go back to plain text. It adds an extra dimension to your note taking making them so much more powerful and useful.
XMind is mind-mapping software with iconos, labels, lines, notes, boundries, fishbones (for timelines!!), Gantt Charts, and easy import, export, pdf, word, ppts, and embed options. It is open source, so it is free to download and use.