Scientifically speaking, this is "an anamorphic illusion drawn in a special distortion in order to create an impression of 3 dimensions when seen from one particular viewpoint." In plain English, if you are too cheap to get yourself one of those Heliodisplay babies, get Julian Beever to paint your ad so that it "looks" 3D. Also, check out 3D Media Solutions, they do decals that work on the same principle.
--via BrandNoise
