Typical mobile devices have in the past included a single keyboard or keypad that allows the user to interact with the mobile device. However, as mobile device technology has evolved, mobile devices have been used for an expanding number of applications. A mobile device such as the cellular telephone or pager may now also be used as a data device, allowing emails to be sent or received, short messages to be sent or received, or even browsing the Internet, among other features.
In order to accommodate various applications, mobile devices in some cases utilize hidden or alternative keyboards. Examples include the Nokia 6810™ messaging device which includes a standard T9 keypad when the device is in a closed configuration and a full keyboard surrounding a display screen when the device is in an open configuration.
Similarly, the Siemens SK65™ mobile phone has a standard T9 keypad when in a closed configuration and a full keypad that can be rotated from behind the standard keyboard to reveal both the full keyboard and the T9 pad at the same time when in an open configuration. Another device is the Sony P910™, which includes a T9 keypad which can flip down to reveal a full keyboard.
The above devices and other devices similar to them allow a user to enter various applications from the T9 keypad but typically do not allow any functionality such as text input or navigation without using the alternative keypad. This is problematic when the user is more comfortable with one keypad over another, when a user wishes to use only one hand to enter information, or in similar situation in which it is preferable to use one keypad over another.