From Chris Kurhan:
Llama Music Cleanser uses your favorite media player like iTunes, Windows Media Player, Zune Software, or Winamp to help you sort through your messy music collection and remove any and all songs you just don't want to hear anymore. With it's simple, easy-to-use interface, managing your music has never been so effortless. All you have to do is select the music folder you want to "Cleanse" of your bad songs, pick your favorite media player (Windows Media Player by default) and rate the song good, or bad. Rating it good leaves it where it is and starts the next song in the folder. Rating it bad moves it to the folder where you put Llama Music Cleanser where you can delete the whole folder in the click of a button (or two). And suddenly, your music collection only has songs you want.