I came across this site in my Google Reader news feeds and just had to share it with everyone.
It contains images and videos of all sorts of amazing things ranging from lightning to auroras and craters to shapes in mountains and so much more.
(Image from http://weburbanist.com/)
Check them out at:
http://weburbanist.com/2008/10/24/elemental-natural-phenomena-formations-disasters-photos-images-videos/