The National Do Not Call Registry gives you a choice about whether to receive telemarketing calls at home.  Most telemarketers should not call your number once it has been on the registry for 31 days. If they do, you can file a complaint at this Website. You can register your home or mobile phone for free. Your registration will be effective for five years.

I am pretty sure that each state has their own Do Not Call Registry as well (not sure why we need both, but there you go). 

This cut down on unwanted annoying phone calls at our house by a ton!   It is very a rare event to get an unsolicited call since we registered for this list. For the first month, if you still receive such calls you can politely let them know to remove you from their list as you are no on the Do Not Call list.  After the first month, you should be solicitor call free.  Which is nice, because it means that you can actually answer your phone again!