I'm a big MindManager fan. Mind maps help me organize my thoughts and plans - they just work the way I think. They engage both the right and left brain. I've been working with Michael Scherotter at Mindjet Labs, and he has come up with this outstanding integration between MindManager and Word 2007. This is such an excellent example of the types of things you can do with the OpenXML File Formats, and the Office 2007 Ribbon UI.
What I really like about this is that I can create a mind map in MindManager 6, then export it to Word 2007 and share it with anyone else using Word 2007 (i.e. anyone at Microsoft, and millions of beta users) and they can open it up in Word even if they don't have MindManager. They can make changes, send it back to me, and when I open it up in MindManager I see their changes. A true round-trip.
What a great example of the power of the new OpenXML file formats. So if you are using Office 2007 Beta 2 or Beta 2 TR, try it out.