The Smithsonian vowed that it would open up its digital collection by early 2015, and it's clearly not wasting time as it delivers on that promise. Both the institution's Freer and Sackler galleries have posted over 40,000 pieces of global art online, all of which can be used for non-commercial purposes for free. If you want an Egyptian relic for a class project or a fine Japanese painting for your phone wallpaper, you're welcome to it. It's relatively easy to sort the offerings, too, so you can look just for art from a given period or browse everything from a particular culture. The size of the digital collection is a bit daunting, but that's a worthwhile tradeoff if it means that you can see classics that would otherwise stay locked up in a museum warehouse.
[Image credit: Ito Sozan, Freer Gallery of Art and Arthur M. Sackler Gallery]