I have to confess that I'm more impressed with your reflective process than I am with Prezi as a real-time collaborative tool. Sounds like something I would try! And I'd hope that I'd learn a lot through the process as you have.
Thanks for the post and Jose for recommending http://cohere.open.ac.uk/ He's right that it's messy but it reminds me a lot of Taba's List-Group-Label that I often then add the mindmapping step to.