Does the world need an electronic call screener?
It seems to me that the telemarketers and the public are involved in an Electronic Countermeasures (ECM) war: devices like the Tele-Zapper are marketed, and the telemarketers figure out how to defeat them. Radio Shack offers the "Quick Hang-Up" and AT&T the EZ Hang-up but TMs still get to make you answer the phone again and again.
How about a device that stores the Caller ID of annoying callers (including OUT OF AREA and so on) and simply answers the call and hangs up if they call again? Would anybody buy such a unit from a TV infomercial ($19.95 plus s&h)?