In case you didn't know, I have a symbiotic relationship with my MacBook, one of my favorite things about my Macky is all the sweet free applications people come up with.
For instance, right now I'm trying to outline an essay for my Modern American History class, to help with my notes and outline I'm using freemind, a mind mapping software that's very similar to some other applications out there, only freemind is... you know... free (and also works with Windows and Linux). I remember learning about mind-mapping in the fifth grade or something, but I never gave it a second thought until about a year ago when I stumbled upon this app, it took some getting used to but now I'm a believer.
It's probably not an app for everybody, really depends on how your mind works, but I definitely recommend giving it a try, it allows me to keep more organized notes and if I change my mind (which has been known to happen) I can easily drag and drop and shift nodes around until I come up with something more suitable, also it gives me a place to jot down anything I may be thinking (which I make sure to format using a little cloud-bubble thing so when I come back to it later I know not to take it too seriously)
Anyway here's an example of some of the work I've been doing the last few days, enjoy (and obviously click on the thumbnail if you want to see a larger and somewhat legible version):