The Thiings Collection is kind of exactly what it sounds like, a collection of things. Many things in fact. This site allows you to download and use any of these icons for free for personal and commercial projects. You can either sift through and have fun checking out all the different icons they have or just download the entire collection! They pretty much have an icon for everything with their collection boasting 9000 icons. They really look awesome and even if you are not going to download and use them it is quite fun to just browse and see what you can find!