Bubbl.us is a brainstorming tool online. You can use it to create colorful mind maps online, share and work with friends, embed your mind map in your blog or website , email and print your mind map, and save your mind map as an image. It is free. It would be a good tool for students to use.And it's FREE!
Create mindmaps together as a class, or independently. Great for people like me who hate to draw a mindmap because it always turns out lopsided, or you don't make the boxes big enough!