A new website I've been paying attention to these days is EPOD: the Earth Science Picture of the Day. It's an especially nice companion to APOD (Astronomy Picture of the Day), and features photos of everything from interesting geological formations to refracting spider webs.
Crepuscular rays (sometimes called "God rays") come up pretty frequently on the site. Not only are they beautiful to look at, but they have a simple and fascinating explanation as well.
This morning there were some nice ones over Lake Michigan...
I guess these are more subtle than most you usually see on inspirational book covers and stuff, but look closely and they are still gorgeous.