Meet Matt Lee, the Technical Lead at Creative Commons. He has a good beard, true, but he also believes very strongly in concept of Free Software. Not free as in a free lunch, but free as in free speech. Allow him to explain.
In this video, he explains the four key characteristics that make a piece of software Free. You'll soon realise why iTunes, while it may not cost a cent, is far from free. (Note: there's quite a bit of audio clipping in the video, but, hey, get over it.) [Computerphile]