Hahaa... This is by far my most popular photo on Flickr. Go figure.... ;-) Here's a link to this photo on my personal site.
This wild donkey was bothered by flies and shook his head at the right moment when I snapped the shot. He came up to our car window to get snacks... and I said "You want flies with that?" That's when he shook his head. At the time, I thought he was saying "NO".. but the capture makes it look like he was laughing at my joke. :) Lucky grab! It really looks like he's laughing or saying "YEAH!!!" :-D