Google has a reverse image search, where you can drag a photo from your computer into the search box, and it will find that image on the web. This is great if you're wondering if anyone has stolen your images, or used them in a way you don't agree with on the internet. This would be uncredited instances of you art—impossible to find by simply searching for your own name. I found a few myself.
But the really fun part about searching this way is Google's collection of "visually similar images" that appears near the bottom of the page. You can find images of vastly different subject matter that look pretty similar. Here are a few of mine (on the left) and visually similar images by other people (on the right) that make for interesting complementary pairs.
Click any image to be taken to the source.