How to make anaglyphs
An anaglyph is one of those images that when viewed through glasses with one red lens and one cyan lens it appears 3d. They are easy to make with a run-of-the-mill camera, and image manipulation software such as Adobe Photoshop. My method is similar to Mark Newbold's, however a little more efficient.
These instructions assume that you are running Adobe Photoshop CS on Mac OS X.
Take a photograph of your subject, move the camera over about 10-15 cm in a horizontal line (The more you move the camera the more exaggerated the depth effect will be) and take a second photograph. For this tutorial I will use these photographs of my garden:
It is interesting to note that you can already get a three dimensional effect by crossing your eyes to "join" these two images together.
Open both of your photographs in photoshop.
Select the left-eye image (the one you took from farther to the left). Click Edit -> Select All (or command-A) followed by Edit -> Copy (command-C)
Select File -> New (command-N), make sure the resulting dialogue is on the "Clipboard" preset
Select Edit -> Paste (command-V), the left image should appear on the canvas.
Rename the layer "left" by double-clicking its name in the layers window.
Now copy the right hand image the same way you did for the left in step 3, and paste it into your new window. Rename its layer "right"
Double-click on the thumbnail for the "right" layer. Uncheck the red channel in the "Advanced Blending" section of the resulting dialogue and press "Okay". Your image should now look something like this;
This image is almost done; however the two images are not properly aligned, preventing your eyes from focusing properly for the 3d effect. All you have to do is drag or rotate one of your layers to make it line up with the other one. For my images there is no need for rotation, however there is a need for some vertical alignment. Pick a spot on your image where there are straight lines, I'm going to use the edge of the wooden balcony at the end of the picture. After aligning these two lines we are left with this complete anaglyph: