Just to brainstorm with you on this, so if not phone, what would it be? Suppose we could build any hardware, any form factor, with any sort of input to convey y

Just to brainstorm with you on this, so if not phone, what would it be? Suppose we could build any hardware, any form factor, with any sort of input to convey your wishes to it, and any sort of output to feed back the output of the "eval" loop of it (riffing off REPL) into any of the five senses (yes, let's include smell to...just for the purposes of an unconstrained brainstorming), how would you envision that? I have been thinking about a "hands-free headset" that just talks to you and you talk back. And I wonder how would "apps" look or function in an ecosystem if the only API available was to speech-recognition engine and a text to speech engine?