According to their website, using XMind/XMind Pro with XMind.net's sharing service is a revolutionary way to enable both team brainstorming and personal mind mapping. With this major upgrade, we bring Web 2.0 concepts on community sharing into a popular desktop application.
The best part about this is that they have it for all platforms, Windows, Mac, Linux, and even a pack-and-go for your usb! (which is my favorite things are in the world now a days!)