Who doesn’t like free? Sometimes, you write a blog post and you need a pic to draw those eyeballs, something colorful but also cheap. The New York Public Library has more than 600,000 images online at digitalcollections.nypl.org and if you click “Search only public domain materials,” anything you find is yours to download and use however you want for free. (Make sure you click “public domain.”)
The NYPL collection has everything from scans of menus to greeting cards to publicity photos to stereograph slides – which are like an early version of a View-Master disc. It’s two images that blend into a 3D picture in the right device. If you want to try it out on the image below, try crossing your eyes like one of those Magic Eye pictures that hides a sailboat. That might work too.