OMG! That's my favorite song in the movie! It's awkward though, because the first time I saw this movie I saw it as a catchy, fun song and the once-ler didn't seem so dark-side, but the second time I watched it I totally shrunk down and I'm all "Gawd, he's evil." 0_0
Edit: Did you ever see the movie? In the song when he says "A portion of proceeds goes to charity." He takes out a quarter and puts it in some guy's cup, but the guy's really his dad (or uncle...) wearing a beard.