I use exactly 2 smart playlists. I think the idea is absolutely brilliant, but am having a hard time coming up with things to do with them. Here's what I do have: "Backup". This, quite simply is a playlist of everything added to my library since the date of my last backup, excluding items where the genre is "Christmas" (they get their own discs and get deleted each January and brought back in again each November). Basically, when this playlist gets to about 4 GB (or sooner if I'm playing around with hardware) I burn a data disc from this playlist, change the date to that day and it starts over again. I know iTunes has a backup built-in now, but I made this playlist before that existed so I'll just keep on going this way. "Penn Radio" I have all episodes of the old Penn Jillette Radio Show converted to AACs, and I have a smart playlist that will keep 10 episodes available with a playcount less than "1". It uses live updating so each time I sync my iPod I get refreshed with randomly selected episodes that I haven't heard yet (since they aired that is). It's like my own personal re-run generator. Cool. Even cooler is that once I've listened to an episode on the iPod, next time I go back to that playlist the episodes that no longer meet my criteria (play count <1) are gone so I don't get re-runs of my re-runs on my iPod by accident. So, what smart playlists do you all have?