Concept Map Tools

In class today, I mentioned some concept map tools that I think may be helpful to qualitative research. I have tried Vue, which is from Tufts University and pretty simple to use (and free). Amy had a link to mindmeister on her blog, which I have not used, but which looks interesting because it is web-based (so, no downloading) and can be shared with other users. Also, Lucy asked about using NetDraw, which I have not looked into yet, but it is also a concept mapping tool for mapping and counting nodes and such in a social networking environment. I think I may be adding these as part of the class in the future.