These babies should come fitted as standard with every phone line. This nifty gadget is a TrueCall Nuisance Call Blocker . This cool piece of hardware is your personal call screener for your home phone.
It maintain two lists of caller's numbers: the star list (your friends and family) and the zap list (the pesky marketers and nuisance callers). People on your friends and family list get put through straight away, but the irritations on the zap list are told politely to go away. When someone or something phones that doesn't provide their number or are not on either list, then the TrueCall asks the caller who they are, calls your home phone and tells you who is calling. From there you can decide whether to "zap" the call, get the TrueCall to take a message, or take the call.
How cool is that? And it is an answering machine as well!