In Grad school my classmate, Fish, turned me onto mind mapping. I don't know if I would have made it through school without it. It really helped me organize my notes in a way it was easy to review and absorb, if that makes sense? Finally I was now able to take notes closer to how I actually thought. And studies have show that mind mapping increases learning / study efficiency up to 15% over conventional note taking (1). Since then I have been using mind maps at work and any other time I need to take notes or brainstorm.
I know other people use mind maps for other things too – Problem solving, prioritization, non-linear lists, etc.