A Raspberry Pi UMPC. An open platform device to use and create. It is fully open-source hardware. So you can modify it as you wish. You can make your Add-ons like GPS, Radio etc and attach them. You can access all the ports of the Pi, and the back part is attached with 4 screws. It can hold a 4" or 3.5" touch screen. You can also have a physical keyboard attached via USB. It doesn't need a custom image of Raspbian. You can use vanilla Raspbian and install the LCD driver, that's it.