I don't think this counts as a glitch, but then again, the makers of this game wouldn't want you to enter Grubb Village's Cave like this:
http://www.youtube.com/watch?v=qvzJOIM9CC8
Also, I found a very strange OoB glitch that destroys the graphics of everything but the boat:
http://www.youtube.com/watch?v=bQBkM4Rfrf0