I saw this on Martha Stewart and immediately wanted to do it. I'd never made cream puffs so the whole multi-step process took me a LOT longer than it probably should have. But seriously yummy... So here is what it's supposed to look like...

And here is my first try...

Not quite as fancy but I heard they often use a Styrofoam cone in the center to make the shape so for having built it completely of puffs, I think it turned out pretty good. The guys we gave it to are serious cooking gurus and complimented me on attempting it and said the puffs were identical and well-done. I think they just liked having real cream puffs.
Recipe at http://www.marthastewart.com/recipe/john-barricellis-croquembouche
I might try to make another for Christmas.