GrandCentral (grandcentral.com) allows you to get a second number that can forward to any phone, and you can selectively forward, block numbers, and use a whole

GrandCentral (grandcentral.com) allows you to get a second number that can forward to any phone, and you can selectively forward, block numbers, and use a whole host of other features. Brring! (brring.com) allows you to get a second number that forwards to your phone, and plays 10-seconds ads that you get paid for.