Last.fm: 12 Ways to Scrobble
“Audio Scrobbling,” as defined by Last.fm, is the act of submitting to a central database the details of what songs you’ve been listening to (what album, by who and when you listened). Scrobbling to Last.fm is the main reason I use the service these days, especially since it made the internet radio part of it a paid subscription only service for Australia. I think that being able to easily track and visualise my listening history and share that with friends is a great example of the social internet revolution.
There are a number of ways to have your music scrobbled to Last.fm from your Mac. Which one you chose depends on which fits into your music workflow the best. Read more at The Apple Blog