I don’t know much about Mind maps but I’ve seen expert testers (James Bach and Michael Bolton) use them to plan out their test strategy – usually in a demonstration. It seems like a plausible way to build test cases or outline a test strategy since a picture can be easier to understand. Has anyone used Mind Maps this way or found value in them for testing?
Read MindMapping 101 from Darren McMillan - http://www.bettertesting.co.uk/content/?p=956
and this discussion ( prompted by myself ) on the STC - http://www.softwaretestingclub.com/forum/topics/im-the-map-im-the-map-im-the
They are nothing new, use of them seems to come in waves - as your question demonstrates :)
I wrote this recently - http://rosiesherry.com/2012/05/mindmaps-testing-pinterest/
My theory is that we can learn from other people's mindmaps and it would be useful to have a bunch in one place - I've used Pinterest for this because it is easy and visual, am sure there are other ways.
Yes, my team has been using Mind Maps to write and run our test cases for over a year now with much success. My team like to use them as you can visually see what has been tested, and not been tested. I've blogged about it some as well. http://testerstrek.blogspot.ca/
I personally use mind-maps for any activity and one of the activity is creating test coverage mindmaps, test strategy mindmaps that I share with my team members and customers.
I love the markers which help in tracking my tests if my mindmap if developed as test design reference.
This mindmap repository may be helpful for you and its open source! You can download various testing mindmaps at http://apps.testinsane.com/mindmaps/ This is released under MIT license which means no restrictions at all! Use it however you love to :-)