Phantograms
Phantograms are a very special type of stereogram. Although you will see a stereographic effect by looking at them on the screen, in order to view them correctly you will need to print them out and lay them flat on a table. Then assume a position in front so you are looking down at the image at about a 45 degree angle. These are cross-eyed type images, so cross your eyes. The objects should look as though they are rising from the table. Then move your head side to side and things appear to move.