A guy I used to play with liked to tune down a whole step (as above) because he said it was easier to sing in that tuning, and he said a lot of bands did that (which I don't find to be true).
Great vid! I always like watching that one. I used to have a guitar that I tuned down a whole step because it is easier to sing and I know of a some songs that sound WAY better that way. It is also a great way to play along with another guitarist and sound cool, since you're playing the same "chords" but in different voicings. Also, you just capo at 2nd fret and you play along with anyone.
As for songs that were done that way:
almost every song by the Velvet Underground, i.e., Sunday Morning, Sweet Jane, Heroin, Rock and Roll, etc.
Most of CCR including Bad Moon Rising, Proud Mary and Lodi
Many Neil Young songs like Hey, Hey, My, My, Sugar Mountain, Rocking in the Free World
If you play these songs in this way, it really gives you that exact sound that seems to be missing when you do it in "standard" tuning.
"The only funeral you should ever try to interrupt is your own, and that should be a full-time job." -Kinky Friedman