I'm not sure why this didn't make a bigger splash in the blogosphere, but I've just had a client of mine show me one of their designs in a pdf as a 3D model! You can rotate, pan, zoom and even change the lighting on the subject matter. Very cool stuff – and as far as I can tell you only need Acrobat 7 to view it.
Check out this pdf example from the Adobe site: http://www.adobe.com/products/acrobat/pdfs/3d_pdf_demo.pdf (be sure to click the buttons at the top to see the animations)
Can't to see what implications this could have with the forthcoming Apollo framework and the convergence of Flash and Acrobat.