I made a little bit while I was in high school (last year) We had a music tech lab. I used garage band to start but quickly changed to Logic Pro. It's mostly loops and some of my own guitar playing.
http://www.reverbnation.com/charliemccowan
The song "Serious Injuries May Occur" was made using loops in combination with the sound files of the popular game Portal. I made lyrics by editing and combining lines from the game. A warning, it is a little on the dark side following the nature of the game.