Build Your Own Tiny Portable Raspberry Pi
The Raspberry Pi is a great little device for portability, and when combined with a touchscreen and lithium battery, it gets even better. Adafruit demonstrates how to create your own.
You’ll need access to a 3D printer for this, but otherwise making your own small portable Pi is pretty easy and inexpensive. It uses the A + model, so its form factor is very small and portable. Visit Adafruit for a complete guide.
Touch Pi: Portable Raspberry Pi | Adafrut