[Wondermonkey]

I used to carry around all my music, and when I got the iPhone, I decided that I'd dedicate only 4 GB of it to music. Since June 25th 2007, I've found that it not only forces me to branch out music wise, but I wind up listening to more of my collection that I didn't even know I had. I set up iTunes to create a smart playlist that adds any song with a less than playcount of 2 to this playlist, and I have it max out at 1000 songs. It keeps it fresh because as a song gets above two plays, it gets removed automatically from that list.

I wind up going "Damn, I didn't even realize I had this" more often than not.