We're written about OBJET's amazing PolyJet technology before, but recently we ran across a great video that shows several truly interesting applications of this feature.
For those who haven't heard of it, PolyJet enables the printer to use more than one kind of material during a single print run. In other words, you might have soft and hard portions on one model. Of course, you could attempt this on other printers, but you'd end up doing multiple print runs and assembling a bunch of parts afterwards. Worse, there are probably some designs you simply cannot do unless you print them in a single run.
Consider this example, where an entire bike was printed - including soft wheels and a hard frame. Oh, and the wheels turn too!
Via YouTube, GodMode and Life and the Feeding Edge