Reader comment: Pete Mortensen says,
I took the big JPEG of Apple's products by Edwin Tofslie and turned it into a visual map of Apple's overall product family over time: Link. You can see families appear grow, and contract - it really tells quite a story. Interestingly, Apple goes into chaos in about 1987, the second Jobs leaves, and only fixes itself once he comes back full time, 1998.
I've uploaded the huge PDF (made in Keynote, of course) to Scribd, where it can be viewed at various levels of zoom in Flash or downloaded as a PDF, and I have this link to where the source file can be downloaded and edited into its own new map, rearranging as people disagree with my choices.