In 1983, Motorola introduced the first cellular telephone in the United States. Called the DynaTAC, this bulky device bears little resemblance to the mobile phones of today. Between then and now, handsets have undergone a dramatic evolution, changing as much in terms of aesthetics as they have on the inside.
One of the first major design innovations in cellular phones — besides making them smaller — was the concept of flip-open handsets. Motorola was the innovator in clamshell design, introducing the first hinged "flip phone" in 1996. The StarTAC has become nearly as iconic as its DynaTAC predecessor, or its later Motorola-designed successor the RAZR V3.
Touching the future
Believe it or not, the first touchscreen-based cell phone actually debuted before most other design innovations saw the light of day. IBM introduced the Simon Personal Communicator in 1994, which featured a pressure-sensitive black & white screen in lieu of physical buttons. It also came with a stylus for taking memos and the phone could actually send faxes.
Despite these similarities to today's smartphones, it wasn't actually considered one. That honor went to the Ericsson R380, released in 2000.
A year earlier in 1999, Siemens ushered in another major design innovation with its SL10: the slide phone. This style of handset covered the physical keys with the screen when not in use. Slide designs were used by other manufacturers for later handsets that hid full QWERTY keyboards beneath the slide-open screen, such as the Danger Hiptop (which later became the T-Mobile Sidekick).
Enter the iPhone
The title of first touchscreen cell phone might be held by the IBM Simon, but the handset that brought the concept into the modern era was Apple's original iPhone, released in 2007. The iPhone set the design benchmark followed by nearly all subsequent smartphones, namely one that incorporates a large multi-touch screen and very few buttons on the front — the iPhone only has one, and most now only have three or four at most. The iPhone has also led the charge towards thinner handsets.
Behind the glass
Since the launch of the iPhone, smartphone makers have been focusing on refining the flat, thin aesthetic that emphasizes the screen over anything else. This has led to the wafer-thin, large-screen likes of Samsung's Galaxy Nexus and flagship Galaxy S III, the latter sporting a nearly 5-inch screen and 0.38-inch thickness.
It's also shifted focus away from major physical design innovations and onto the feature sets of phones. This has led to advancements in camera quality, data download speed, and processing power more than anything else. Innovation in software, such as Apple's ongoing evolution of its iOS operating system, Google's colorfully named Android iterations, and the rebirth of the Windows Phone platform, have also picked up pace.
Still, it seems like screen size will always be a focal point of designers. Samsung's Galaxy S III is considered at the top end of usability at 4.8 inches and phones like it have reportedly spurred Apple to target a larger display for its next iPhone.