MindMeister is an online collaborative, knowledge-based mind mapping too, it has been built from the ground up to facilitate collaboration. You can share any creation easily by inviting users by email, or simply send them a unique and secure direct link.
You can start a thinking session and collaborate on any mind map in real-time. Color-coded effects will highlight changes by other users within seconds, and the integrated live chat will let you exchange thoughts with your peers directly. http://www.mindmeister.com
Mind maps help users collect ideas and facts based on a given topic. Mindmeister has many applications beyond mind mapping, including creating to-do lists, project planning, designing timelines, and brainstorming.