One of the coolest music discovery app for iPhone has just been updated to version 4.0 with several new features including Facebook integration.  The latest version of Shazam now lets you see a feed of song that your Facebook friends have recently tagged. This is done through the new option “Shazam Friends.”

Shazam lets you identify songs playing on the radio, on TV, or anywhere in the real world by holding your phone up to the sound. You can also tag and purchase tracks through Shazam.

The new social features let you navigate through the songs that your Shazam friends have recently discovered. Through the said feature, you can listen to the music which your friends have tagged as well purchase them online.

Shazam 4.0 will also let you post tags to Facebook and Twitter, add comments as well as give your friends a chance to listen to music you’ve tagged if streaming services are available. To enable the Facebook-specific feature, you must log in to your account and allow the app to connect with Facebook.

Shazam is available both as a free download and premium version ($5.99) from the App Store.

Shazam is a service for mobile phones that lets you identify songs by playing them into your phone’s microphone. It’s available for iOS, Android, and other platforms. The iPhone version of Shazam is available as either a free, limited download or a premium full version called Shazam Encore which sells for $4.99. And starting today, Android users have the same two versions to choose from.

The free version of Shazam will let you identify up to 5 songs per month, while you’ll have to pay $4.99 for Shazam Encore if you want to remove the 5 songs per month limit.

On the other hand, Shazam Encore does have another key feature that you won’t find in the free app: it links to Pandora, allowing you to create internet radio stations based on tracks you’ve identified with Shazam.The Encore edition also get music recommendations based on the songs they tag.

If you download the free version of Shazam from the Android Market, you’ll be able to use the premium features for 7 days. Existing Shazam users who already had the app installed on their devices before July 14th can upgrade to version 2.0 and keep the unlimited tagging functionality.

via Android Guys