@erikvold
The Daily UserScript: Last.fm Ads Remover
This userscript removes a large amount of known ads from Last.FM. It doesn't get them all, but it removes quite a few.
The Unpleasantry:
Seeing ads at Last.FM.
The Alleviation:
Once you install the "Last.fm Ads Remover" UserScript all of the areas where I have ever found ads on Last.FM are gone.