Handset cohabitation: Ubuntu for Android

Combining a physical keyboard and monitor (but no mouse) with a tablet is feasible (Bluetooth or USB work, even on an iPad, via the Camera Kit) and in fact quite a few iPad users do this, mostly when they want to actually write something significant.

I'm looking at this for someone who is finding even a locked down PC too complex (multiple tabs and windows create great confusion), and needs more of a kiosk/tablet type experience.

For a smartphone, Ubuntu for Android may make sense, but for tablets you might as well use the native tablet apps on the tablet screen, and just add a keyboard as needed.