KaraokeParty is a music service that lets users sing karaoke, practise singing and challenge friends. All that is needed is a microphone and a computer connected to the Internet.
You can choose to sing along with the music and vocals or just the music (harder!)
All music on the site consists of cover versions made by professional musicians and not the original artist, so there should be no problems over copyright.
Verdict: A good selection of songs, a well-designed interface and lots of community features make this a great site for improving your English (and your singing).