I disagree with the previous reviewer. The interface is a little unMac like, but with software this good and powerful, and at such a bargain price, who cares?

I've tried a variety of mindmapping / idea organizing tools for the Mac, and this is head and shoulders above the others. It is extremely easy to use and get started, but is also very powerful with plenty of additional features to keep you busy. You can produce some stunning visuals with it. The support is excellent, and updates are frequent. The product is extremely stable, and the quality of builtin and online help a model for all applications. Don't take my word for it - try the demo.

You should also check out the full product, Novamind; there is a good comparison on the site between the different versions.