[ericrallen]

There are lots of computers with touch capabilities out there.

From the gesture support on Apple’s trackpads to touch screens like the Surface (and plenty of other laptops with touch screens).

There are also stylus inputs and things like Wacom tablets that have been around for many years now.

[kedean]

There's also microphones and cameras that can act as inputs, it just turns out they don't offer much power over kb/m.

But really, the problem being solved by OP was not enough outputs, rather than not enough inputs.