So I have been really loving Itunes 8 this week: and in particular the new genius feature.
Select any track and click the genius button. Itunes then uses your listening preferences and the chosen track to build a playlist (from 25 to100 songs) of similar tunes it thinks you will want to hear (in your library).
It's awesome. I hadn't realised how stuck into a static playlist i had become. Very rarely did I listen to any tracks outside of about 50 or so I have in my main playlists. And according to last.fm most of that consisted of Hurt or Linkin Park.
I admit that Genius has not got me listening to every song in my library: but I have found myself listening to lesser known songs from my favourite artists. Its been quite fun because it adds a bit of variety to my day (as I listen to a lot of music: hate quiet).
The only gripe I have is that my Ipod Nano hasn't got an update to include genius - now that WOULD be awesome considering I use it almost every day. Still it's an excuse to go and buy and Iphone soon :D