A new project turns the Raspberry Pi into a completely portable PC with a display and a slide-out keyboard. Reminiscent of the HTC Dream, Sony VAIO UX or T-Mobile Sidekick, the MutantC_V2 also incorporates a built-in battery.
https://www.notebookcheck.net/Raspberry-Pi-Turn-the-popular-single-board-computer-into-a-handheld-computer-with-a-slide-out-keyboard-and-display.459987.0.html