This is so cool! San Francisco-based artist Josh Ellingson has posted a detailed tutorial on how to make a 3D illusion effect in Photoshop. This type of 3D art is called an anaglyph and it requires those special red and blue glasses to see its depth. (Interesting side note, Josh recommends wearing a pair of those 3D glasses just to work on the art itself.)
One way to merge two images together from different vantage points to simulate the distance between your eyeballs. Another method is to have software shift the red and blue using what's called a "depth map". There are even apps that allow users to cut up a flat image into chunks and then adjust how far forward or backward to move the chunks. All of those ways are destructive to the final image and are usually done as the last step in the creative process. As it turns out, there's a much more flexible way to do this buried inside of Photoshop's 3D functionality. It's easy and I can't believe it's been right there for a long time.
Spoiler alert: As it turns out, Photoshop has a robust "3D workspace" that includes an anaglyph feature.
Josh made the 3D artwork that's featured in the tutorial for the cover of sci-fi surf rock band's Aloha Screwdriver's 7-inch EP, Above Snakes. When you buy the 4-song album, there's no need to source a pair of 3D glasses too. Donald Bell, the guitarist for Aloha Screwdriver, tells me the record comes with them, "of course." He also reports that the vinyl is a "cool translucent blue."