I have noticed a significant increase in the spam calls over the past couple weeks - like as of the new year, they had a greatly increased quota or something. I'm now getting somewhere between a few and a dozen calls every day. I never answer the land line unless I recognize the caller ID. Sometimes I just unplug the phone for the day.
It's been quite a while since I actually picked up and got one of these scumbags, but every time I do, I make my mission to 1) keep them on the line as long as possible to waste their time (pretty easy), and 2) do my best to bring the person making the call to tears. That's harder, but a worthy goal.