I like www.mind42.com - a decent web based mind-mapping tool that allows you to share the mindmap with other people. Also it's free, which is a plus. I like mind-maps for any kind of stream-of-consciousness note taking and idea documenting.
I might look into this - I have my maps synced via Dropbox but as MindNode is a native Mac app I can't get access when I am on a Windows box.