Idea:
a #Plan9OS phone with a trackball/-point and three buttons on its side, running a modified window manager.

There has been a port of #InfernoOS for #Android that did something similar but it'd be cool to have native mouse buttons and proper Plan 9 instead of a VM.

(btw, how should I tag these? because both "Plan 9" and "Inferno" are ambiguous and hard to search for, but adding "-OS" feels weird.)