Last month I marveled over the cute LastGraph which shows you a visualization of what artists you've been listening to on Last.fm lately in a neat way. Today I discovered this cute visualization: Tube Tags
I think it's only for paying Last.fm users since it says "VIP" next to the link. My understanding is that it shows the genres of music you've been listening too recently in a London Underground type of map way. Very neat.
Here's mine (31Kb PDF)