A friend posted this video on her blog. It's a cover of this song. It's an amazing song and both versions are so great. Here are some more great versions of it. Funny one Funny, but long, so you might have to skip to the end And I love the voices here on Glee A few days ago my son was singing, "now you're just somebody that I used to know" and I was wondering where do I know that song? It's a great song.