This will be the first of several posts about information appliance and multi-use product issues.
Place: reading a magazine in a store.
Design problem: Interface designers often face a conundrum when designing products. How do you get a lot of features in while still producing a usable product? The above is a real product review in a fairly well read magazine. They have placed an enormous swiss army knife in their overview of 'cool products'.
Design solution: Products fall into a complexity continuum leading from low to high. Lower complexity products (sometimes called information appliances) typically only do a few related things and can potentially have very simple interfaces. In locations such as a kitchen countertop or a large desk, many individual interfaces can be easily accessed and organized. However when we look at mobile devices, the ability to carry (or wear) multiple interfaces is dramatically reduced and the benefits of combination become more apparent.
The pocket knife above has gone so far down the complexity continuum that it has actually ceased to become easily portable. Furthermore the quality of the experience of using any individual tool has become so degraded that it becomes pointless to have that many tools. The opposite can also happen, such as in the iPod, which has an overly simplified interface (no added complexity to support advanced or long-term use) which is used to access a variety of complex features. All good design is about finding the right balance and optimising for what people need to get done.