Apple Prototypes: 5 Products We Never Saw
Apple was the first to introduce digital camera (Quicktake) and PDA (Newton) to a mass audience long time before then became product of mass consumption which is why they commercially failed(can we call it The Tucker syndrome? or maybe the NeXT syndrome for the geekier of you). These products are probably the tip of an iceberg, the hidden part being all of the prototypes that they didn't put into production like the ones described in this article by Apple Gazette (also read the comments for more):
Apple Prototypes: 5 Products We Never Saw by Apple Gazette
One can wonder what else they are concocting in their labs now given the evolution of Apple R&D; budget: