h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Some time ago the direct marketing association set up what is called the Telephone Preference Service (TPS) to cut down the number of unwanted calls under the guise of 'research'. Indeed the TPS has had its own guide entry for some time: http://www.bbc.co.uk/h2g2/guide/a254332.

Although registering with this service does not prohibit market research companies from phoning, the majority of legitimate independent UK agencies, and certainly those that adhere to MRS (Market Research Society) and BMRA (British Market Research Association) guidelines, screen telephone numbers first for TPS registration as a courtesy.

Alhtough several people have already posted possible 'witty' responses to market research interviews, the fact is that most of them deal with scores of people like this on a daily basis - they get paid by the hour, not per interview, and quite frankly probably care less about the survey than you do. The result being that after the call you will be laughed at like a deluded middle aged man at a wedding reception who decides to 'get down with the youngsters'.

Still, some smaller research firms and telemarketing firms may call you, and they're the worst ones to worry about. The best bet is still to get a "Caller ID Block" which immediately intercepts any call from "Unavailable" locations, if you honestly don't want to receive any. Usually such numbers are simply taken off of the list immediately.

Also, as to the second part of that, responses aren't "witty" when they've been passed around the internet for years and appeared on TV shows, etc. :P At least if you're gonna do a "witty" response, come up with your own.