I posted this article recently over on the other blog. I’ve recently become a fan – nay, a fanatic – of social music site Last.fm. It could be described as Internet radio, but with several twists that make it also a music recommendation engine. I started using the service several years ago, but only recently figured out how to truly integrate it into the day-to-day routine.

The service can be used a number of ways. At its most basic level, you can login to the site with a browser and simply play music from the website. You tell Last.fm an artist you like, and it generates a “station” that plays music similar to that artist.

Last.fm knows what’s similar not by someone making arbitrary associations but by the millions if not billions of plays from users who then rate the songs with either a love or a ban. When you click the love button, you tell Last.fm that the song it played is a match to your musical tasts. When you click the ban button, you tell it that you don’t like that song and not to play it again. Last.fm uses this preference information, in addition to the artist you picked at the beginning, to build an enormous database of music relationships.

Using Last.fm at this level is novel and entertaining, but I always found myself reverting back to playing music with the Amarok, Zune or, recently, iTunes music players because the sound quality was better for locally-stored music than that streamed over the Internet. A few weeks ago, I learned how to use Last.fm to scrobble music and everything changed.

Here’s the definition and explanation of scrobbling from the Last.fm website.

Scrobbling a song means that when you listen to it, the name of the song is sent to Last.fm and added to your music profile.

Once you’ve signed up and downloaded Last.fm, you can scrobble songs you listen to on your computer or iPod automatically. Start scrobbling yourself, and see what artists you really listen to the most. Songs you listen to will also appear on your Last.fm profile page for others to see.

Millions of songs are scrobbled every day. This data helps Last.fm to organise and recommend music to people; we use it to create personalised radio stations, and a lot more besides.

With the Last.fm program downloaded and installed, every song played on your iPod, iTunes or other supported music players is recorded on the Last.fm website. This data mining means that the user profile records all music played locally and adds it to the user’s Last.fm library to generate reports and charts, which can be embedded on websites or other social networks like the one at the top right of this post, showing the users preferences.

Last.fm is a music recommendation engine in that it learns what you like and then exposes you to other music that you should like, based on the algorithms and database of music relationships. The accuracy of the system is amazing.

Finally, Last.fm is a social network. What good is music if it can’t be shared? Like Facebook or MySpace, users can associate their profiles with other friends. Once you have a friend on Last.fm, you can actually stream his or her music library. Last.fm also ranks your musical compatibility with your friends on a graduated scale, so you can know how well you would get along with someone on a long car ride.

With Last.fm competitor Pandora releasing a new version of its iPod application within the last 24 hours, it seems like the game is afoot for Internet music. Last.fm wins with its scrobbling abilities, but there are services that will actually allow a user to scrobble Pandora songs to Last.fm. I say just use Last.fm.

If you’re a Last.fm user, add traffas as your friend. Here’s a link to the profile. www.last.fm/user/traffas

Are you a fan of Internet radio? Do you like Pandora more than Last.fm? Tell me about it in the comments.