Teh no-call list seems to work quite well, so I don't get many calls other than political and charity calls, which are exempt. Most of the charities who cold-call me (without my donating first) are questionable, mostly law enforcement and veterans groups that seem to have nothing to do with law enforcement and veterans. I'll listen to their spiel, and then say in a very friendly tone, "Gee, THAT sounds like a ripoff," and then I hang up.
Very satisfying.
-Joe-