A new website and smartphone app that I've been loving is "artstack". If you love art, as much as I do, this is a must have app/site to click on. The idea is similar to a tumblr blog, where you follow other "stackers" and reblog, restack, the artwork they post. You can certainly upload your own artwork too. I've come across contemporary to medieval, there is no limit to what you'll find.
Here is a sampling of art I've restacked on my feed: