After literally months of going through my itunes, I've finally managed to cull out about three gigs of music. This took a few deep cuts (I said goodbye to KC & JoJo's "All my life"!), and I'm sure there's more I can cut, but I'm done with the massive push for now.
29. Get my itunes to 13 gigs of music (currently a bit over 15.5) in my 101 things is now done!