Yahoo reproduced 16 photos that were submitted by readers to a National Geographic contest. Collectively, they are very cool; I recommend checking them out. This one is of dolphins. The person who took it wrote:
I had just finished photographing surfers when this school of dolphins came through. For once I had my camera with me and was able to get the shot!
OK, here is one more, of a waterfall in Iceland called Seljalandsfoss: