While trying to identify my mourning cloak caterpillar, I stumbled across a website called "What's That Bug?". I love it already. Basically, people take pictures of unfamiliar bugs that they find in their homes and send them in for identification. Here are a few of my favorite photos.
Snake mimic.
Even better, they have bug love and bug carnage pages. Here is one (of their many) caterpillar pages.