Stereo photography turns out to be fairly easy to do if you're not concerned with exact results, even if you only have one camera. Choose an appropriate scene and photograph it from two different positions a small distance apart, making sure to keep the camera as horizontal as possible. That distance depends on distance between the camera and the scene, but for most pictures, an inch or two of separation between camera positions is sufficient. Make sure you keep track of which photo you took from the left side and which you took from the right. That'll be important when preparing the images for viewing.
Download the photos to your computer and adjust the images in Photoshop (or a similar program) to compensate for any camera unsteadiness. They need to be horizontally & vertically aligned, color corrected, and cropped so that the two photos look as much alike as possible. The easiest way to do this in Photoshop is to paste one image on top of the other in its own layer. Decrease the opacity in the top layer to 50% and adjust to your heart's content.
When preparing the images for viewing, tall images seem to work better than wide images in getting the proper 3-D effect. Keep image sizes small; if the images get too wide, you won't be able to cross your eyes enough to see the effect. To view the images, place them side-by-side on the screen or print them out, placing the photo you took from the right side on the left and the photo you took from the left side on the right (if you don't switch the photos, you'll get a strange inverse 3-D effect). Then cross your eyes until a composite image appears in the middle.
__________________ If ever there was someone to keep me at home, it would be you.
true stereoscopic photography needs to have a base to mount a camera on where the center of the lens element is the same distance apart as an average mans pupils. Easier to have two cameras mounted this distance apart on a special tripod mount so that you dont screw up perspective when you move the camera from one side to the other.