I know, that's a mouthful of a title. MindMeister is an online, collaborative mind mapping tool that lets multiple users edit a common mind map. Essentially, its a visual wiki, that allows anyone to makes changes to the data, but you need to be logged in so that it can track who makes the changes.
Andrew Wilcox has created a public mind map with the catchy title "The Strengths and Weaknesses of Mind Mapping Software Applications". You can see all of the different mind mapping software packages, the pros and cons of each one, and add your own comments.
Your voice can still be heard, a few of the software applications don't have any comments at all yet. They need people to help add information to the map.
Also, MindMeister has an iPhone app that allows you to view and edit online mind maps from your iphone. It's $6.99US in the iTunes App Store.