Here's one of my own, now that I've finished the book.
<a href="http://www.flickr.com/photos/dotdoubledot/2208867228/" title="Sun and Signs by .: sandman, on Flickr"><img src="http://farm3.static.flickr.com/2168/2208867228_b5ccdca0be.jpg" width="500" height="335" alt="Sun and Signs" /></a>
It's not realistic. I darkened the sky quite a bit and tweaked the color.