Everything is All 3D and Stuff
3D might look like Hollywood magic, but the principle behind making 3D images is pretty simple, and it's based on your average human's eyesight.
It's very straightforward: your eyes are about 2.5-3.5 inches apart, and each acts as a camera sending partial information to your brain. To fake the effect, you need a way to send those two different images to the correct eye.
At home, using two cameras spaced 3 inches apart, or a camera trained on stationary objects, you can take two photos that represent each eye's field of view. From there, Photoshop techniques can be used to remove color information in some of the color channels to produce red-blue or red-cyan 3D images for use with glasses, or simply creating a diptych of the two photos allows them to be used with an old-school stereogram viewer.
Newer techniques can disseminate that information in even better ways with less loss of color. In some cases it can be very light shades of gray and white used to separate the two parts rather than the traditional red and blue.
So if you have photo editing software, 3D glasses, and a camera, go out and give it a shot!