Stereoimaging has always fascinated me, and I've understood the concept for sometime. In high school, I tried my hand at random-dot stereograms. A few years later, I made some 3D text signature files for my emails -- again as stereograms. Ironically, it was only afterwards that I thought of doing the (conceptually) simpler stereoimaging by placing left-eye and right-eye images side-by-side, instead of intermixed with each other.
The process of creating the images was surprisingly simple. For the raytraced image, I took a raytracer that I had made for a graphics class years ago, and created the two images with the camera a view units apart in the X direction. As for the photographs, I took two pictures of each object, one while looking through the viewfinder with my right eye, and then one while looking through the viewfinder with my left eye (without moving my head). For each picture, I made sure that the center marker of the viewfinder was framed around the same spot.
Here are three of those images. The images are laid out for parallel or cross-eyed viewing. Parallel viewing is where the left-eye image is on the left, and the right-eye image is on the right. So, you'll have to relax your eyes to see it. You can also think of it as looking "past" the images, so your eyes converge on a point further away than the images themselves. Cross-eyed viewing is where the left-eye image is on the right, and the right-eye image is on the left. So, you'll have to cross your eyes to see it. I've provided 3 different sized images for each, so you can pick the size that's easiest for you.
Here are the text-based stereograms I created: p>
Jesus saves (This one is rather hard)