You could sign up for a service where you'd get a list of, say, a dozen unlisted phone numbers. You could give them out on product registration forms, to potentially scary blind dates, or other people you may want to avoid in the future.
If the recipient of a particular number proves to be someone you'd like to avoid, you would call the provider and ask that the number be disconnected (giving the standard "no longer in service" message -- as though you had moved or hadn't paid your bill on time).
To avoid cluttering up the public numbering plan, this could also be implemented as a sparsely-populated set of extensions from one central number, like voice mailboxes. Depending on turnover, the numbers could be recycled periodically.-- frankus, Apr 11 2003 Rejection Phone Line http://www.rejectionline.com/similar in spirit [rahulb, Oct 04 2004] Nah, why recycle them? We need more area codes. +-- snarfyguy, Apr 11 2003 Oh, how I enjoy ten digit dialling! And I simply luv the idea of each city block needing its own area code. Bring on the false paper trails, blind alleys, and pure fraud. Let the fishbone I am giving you serve as a lesson. Instead of a dozen numbers, you just pay for one unlisted number. Use that number for your family, close friends, your work. Use your existing number for all those undesired contacts you anticipate not wanting to talk to and put just an answering machine on the line. That way you have the exact solution you described. Don't want to talk to any of those callers? Change your machine's message to "this number is no longer in service." If you like, you can monitor the incoming calls with call display. Anyone smell baking?-- Canuck, Apr 12 2003 "I'm sorry, but I'd rather not give you my phone number."-- Don Quixote, Apr 12 2003 Wouldn't it be simpler (and more honest) if there were a number that could be given out that would be universally understood as 'DON'T CALL ME'. That way, the recipient saves face (they are still seen getting your number).-- Twibble, Apr 12 2003 What's wrong with caller id?-- Worldgineer, May 09 2003 Twibble - How about the ever popular "anything with a 555 prefix"?-- BayRatt, May 10 2003 random, halfbakery