Nice effect.<p>I think a bit of JS is being used to create the DIV structure, but that's not important.<p>It could also be improved a bit: you could remove the shading gradient from the Coke can mask PNG, and render the shading using an CSS gradient with RGBA values.
That would mimic the specular highlighting, and you could also animate the shading.<p>I still haven't quite grok'd the displacement method though... it must be carefully calculated background x pos offsets? (I don't have firebug on this machine)