Recommended · for some experience
Raspberry Pi Laptop with Atrix 4G Dock
Why people recommend it
An Adafruit guide to turning a cheap Motorola Atrix Lapdock into a Raspberry Pi laptop, a frequent answer when portable Pi builds come up.
Watch for: Involves splicing a USB cable; power backfeeding tricks vary by Pi model
In their words
I've been seriously looking into making one of the Raspberry Pi Laptops that have been floating around using the Motorola Atrix Lapdock solution found here and here.
M. Choi on raspberrypi.stackexchange.com, Dec 2012. CC BY-SA.