The three tools I've used for presentations are;
1) www.Bubbl.us - web based, collaborative, basic (free).
2) www.Mindmeister.com - a map of web 2.0 tools - web based, range of useful features even with the free version. The premium version expands the feature set.
As you can see from this example my techniques improved markedly after attending an approved Buzan mindmap session. If you adhere to the principles, it really does help improve memory, recall, and trigger ideas off from all areas of your grey matter.
The best I'd recommend for teaching and learning was one I reviewed a few years ago, called mindgenius. The ability to export skeleton maps to word documents allowed students to rapidly work round ideas, then export nodes as word subheadings. Ideal planning tools for both visual learners and anyone coping with dyslexia.