Music-recommendation tools The Filter has launched a Facebook application that enables users to recommend songs to friends. Facebook users with The Filter installed can organise their digital audio files and share musical interests.

The Facebook application of The Filter allows users to listen to clips of songs recommended by friends.

Originally launched as a beta for Windows XP PCs in 2006, The Filter is now available as a free download for Windows, Mac and Nokia Series 60 mobile phones. The Filter works with iTunes and Windows Media Player and enables you to build playlists by analysing the music on your computer.

The Filter learns your music-playing habits and uses this to recommend playlists that you can later transfer to your iPod or other portable music player - or via the Facebook application, to your friends. The latest version of The Filter features an improved interface and includes a way of generating playlists as if they have been selected by celebrities or your friends.

The Filter can identify 5 million songs and currently has a user base of around 25,000. British software company Exabre developed the engine and it has also been backed by Peter Gabriel's Real World Group and Eden Ventures.

The Filter's engine is currently available only to generate musical playlists but its recommendation technology could work for other forms of digital content.