Vidya sterograms
Not sure if I posted this here before, but I once made some Skyrim stereograms, the type of images that appear to be 3D if you look at them cross-eyed.
These images here are quite large, so you may need to either 1) step back from your monitor or 2) resize your image viewer.
How these work: Each image represents the POV from each respective eye. When you cross your eyes so that the two images converge, you get the same effect of focusing on a physical object with your eyes. While viewing, you can even adjust your focus to objects further in the distance just the same as you would with a physical object. With FPS games (probably any 3d game really, even sidescrollers), these images come out extra clear since the 3D effect mimics real life environments.
How to make your own:
>Find a game that supports freezing time while also allowing you to freemove
>Position yourself in front of an object or scenery that you wish to capture as a sterogram
>The first position will represent your left eye. Take a screencap
>Now move just a tad to the right. This new position will represent your right eye. Don't move too much or this will simulate what it would look like if your eyes were that far apart. When in position, take screencap
>Open both images in an editor, position the first screencap on the left and the second on the right. Save image
Anyone want to take a stab at making your own?