Portable pentester? that tiny calculator would only be capable of of few things regarding pentesting, given its power and ARM CPU for which you can't install any distro you want. A netbook (Acer Aspire One) might be a better choice.
I disagree, sure it wont be cracking hashes anytime soon, but there are distros avail for the pi specifically for pen testing. From metasploit to aircrack has been ported. People even stick them in drones for an aerial assault, or go war driving in a car. Also seen them being used at atms for carding and all you'll need is a smartphone to pull the data from it.
As for the screen, if your going touch screen, use a capacitive touch screen and NOT resistive. Other than that, and Pi modual screen would be fine. I would recommend a small bluetooth keyboard/touchpad. An Xbox360 controller ith the keyboard attachment is promising. OR fuck a screen and use something like VNC and just use your phone/tablet for interaction.
Pi's or anything embedded is useful. Stick it in a backpack or something and connect with your phone. In public places, if you pull something epic or bad off, the cameras only see you fucking around on your phone like everyone else, instead of being suspicious on a lappy.
