The Like.fm client for OS X is an unobtrusive and lightweight menulet item that starts and stops with iTunes.
Give us better data so we can give you better recommendations, better capture your musical essence, and feed you tidbits (like old favorites you forgot about).
Rate songs directly from iTunes and have it instantly reflected in your profile to share with friends
Listen to internet radio, and keep a history of the songs
Barely uses system resources and only runs when iTunes is running.