I was chatting (via work's internal chat system) to a coworker, answering a question when the CFO came in and got my attention. I swivelled my head and greeted her while finishing my response.
"Were you really typing just then?" she inquired.
"Yes, until I dropped my train of thought when you came in."
I'm not a classical touch-typist; I mostly use six fingers or so, and I don't really keep them over the home row -- rather, I have two or three hand positions that I can feel properly, and that's where I type from. My speed would probably be improved if I practiced proper touch-typing, but on the other hand, maybe I would lose my ability to type the arcane symbols of computer incantations that are not so common in the mainstream typing systems.
Do learn some form of typing; it's ever so much more convenient for getting your thoughts out.