I’m no visionary, but I’m pretty sure this needs to happen:
Right now, your cell phone has two modes: on, so you’re constantly interrupted, and off, so you can’t be reached at all. I think we’ve all found ourselves in that situation where it’s not a good time to answer the phone, but feel we need to because “it might be important.” Perhaps you, too, have lost karma points with your beloved mother by answering the phone at work, then failing to find a sufficiently politic way to say “I answered the phone because I thought this might be important, but apparently it’s not.”
Our workarounds rightnow are pretty unsophisticated. We answer virtually all calls, wasting time or focus. Or we ignore virtually all calls, using voicemail as a makeshift screening mechanism. We try to guess what the caller is calling about. We say to ourselves, “If it’s really important, he’ll call again in a few seconds and then I’ll know.” We even get pre-call texts like “Free to talk?” or “Call me when free”–a pre-call call, almost.
So, there should be some call-screening settings based on your current availability, like:
Setting 1: Open availability. Caller gets through immediately.
Setting 2: Limited availability. Caller is told that it’s not a good time, but if it’s a quick and/or time-sensitive matter, he can get through by pressing a button.
Setting 3: Emergency availability. As above, but for urgent matters only.
Optionally, there could also be settings based on who is calling, whether it’s a whitelist (“allow family members only”) or a blacklist (“don’t allow that one guy”).