I was in Jekyll Island last week attending the Georgia Environmental Conference and saw this beautiful scene outside my hotel window one morning:
The rays which appear to be stretching out from the horizon are called crepuscular rays, and are actually beams of sunlight shining through breaks in clouds below the horizon. You can often see crepuscular rays during the day when strong sunlight shines from behind clouds, especially when the air is dusty or especially humid, making the light more visible. Here is a nice example from Commons Wikimedia (a great source for images you can use in presentations).
The link to the image above is available here.