I always loved the stereo mix of "Don't Worry Baby" - with a left-right 
balance control you can isolate Brian or the background vocals.

Heres a MP3 of the right channel only.
http://planet-zero.org/~wildbill/DontWorry.mp3

The boys "oooohs" throughout the song are just amazing, and they just 
knocked this off as a quickie b-side.

Billy