In my book on product design, Interfaces.com, I talk about a shift from evolutionary product design to the current model of version numbering. There has been a murmur of disappointment this last week when Apple issued iPhone 4S instead of the expected iPhone 5. The new features of iPhone 4S are exciting, new, and unexpected (think Siri). So what’s the problem? Is it really that the version number is too low for our expectations? In the days of yore, no one has ever heard of version numbers. What hammer do you own? Is it version 1.0 or 5.0? Do you care? We have many different types of hammers in our garage, but we don’t think of them in terms of version numbers, rather we focus on what they were designed to help us do: hammer a nail in the wall; pull out a nail; tack in the a little staple in the floor boards; create a hammered copper art piece. Each task requires a different approach and a different tool. And each tool was carefully and systematically honed to perfection by thousands of years of human use: from stone hammers to our tools in the garage a continuous progression of…