SpiderScribe is a new mind mapping tool that does more than just organize ideas. It also allows you to add pictures, documents, Google maps, and adjustable notes. A calendar item is also available. Best of all the mind map resides in "the cloud" so can be accessed from any location. It can also be shared and multiple, simultaneous edits are possible. It does use Flash, so iPad use may not be possible if you have not added the Flash plugin. Registration is Free. There is no limit to the number of mind maps you can create.
See a 2 minute video about use of SpiderScribe. Teacher training videos are available here.