We still have a landline, which has caller ID. Our phone also "announces" who is calling. It says call from...what/whoever. We simply ignore it if it is someone we do not know. Anyone that is calling with anything of importance can/will leave a message. We don't even have to go look at the phone, just listen for the info. Our phone has the ability to block numbers, and I utilize that also. The do not call list has helped, but is by no means a cure all. So far I get very few calls on my cell phone. Any unwanted calls get blocked.