Background

Palm introduced upgraded wireless services, including a built-in cell phone, with the launch of the Tungsten C in 2002. The Tungsten C had a thumb keyboard but no numeric keypad. All voice dialing functions had to be managed through an onscreen interface.

The project

With a physical keyboard users can make calls with one hand without looking at the device. There's no way to simulate the tactile feel of a cell phone button onscreen, but an onscreen phone interface has other advantages. The keyboard can disappear once a call is made, allowing the user to manage calls and call states more easily. And the keyboard is much easier to use than a numeric keypad for entering names in speed dial settings or for sending text messages.

This design performed very well in user testing. The success rate was over 80% for tasks such as placing a call, putting a call on hold, and conferencing two calls.