Mindmeister

Mind maps are a very useful tool for project design and brainstorming. Additionally, with the proper application, one can really benefit from mind maps using them in the context of GTD.
Mindmeister is such a web application. A pure mind map, sharing enabled and smooth operating application which can be really helpful to users with lots of projects.
Users can easily add nodes, remove and move using drag and drop into the workspace which can be pretty quick by using the keyboard shortcuts. Icons can be added to nodes as well as color and specific fonts, making your mind map easy to read. Additionally each node can have its priority, due date and be assigned to another person to complete. You can create more than one mind maps (depending of the plan) to separate your life focus areas.

Killer features:

• All you system readable, at a glance
• Exporting in many formats
• Offline access for premium and business users
• Easy addition of elements

GTD mode: Contexts and projects as nodes connected with each other. Set next actions via drag and drop between elements. Set due dates and priorities on each node separately.

Weaknesses:

• No full list of tasks can be produced

Supported services: Sharing and collaborating, export (Freemind, MindManager, RTF outline, PDF and image), printing, offline access(premium), twitter, email import and notifications, SMS,  iCal feed (premium), folders for organizing mind maps, gadgets for MacOS, iGoogle etc, IE and firefox extensions, API, Google Apps.

Mobile access: iPhone/iPad

Cost: Free, Premium (€39/year), Business (€6/month per user)

Conclusion : With a ton of available services helping you add to your mind maps wherever you are, Mindmeister can be transformed from an experimental solution to a full blown GTD system and give you another perspective on your entire system.

https://www.mindmeister.com