Jobs was reportedly greatly influenced by Sony's late-70s/early-80s design sense, especially wildly popular consumer products like the Walkman. This book has a brief mention of Apple sharing a building with a Sony office in 1977, though I could've sworn I've seen a longer discussion somewhere: http://books.google.com/books?id=W4_P8LDZOmAC&pg=PT38. I think Jobs has actually said somewhere that the iPod was intended to be the "Walkman of the 21st century".
