Well *69 is kinda good I think because for people who don't except blocked calls you can still enter ANY number and the person who has caller I.D. still has no idea who calls

because you enter a bogus number.

I use it when I get calls and I don't know who the person is. I maynot want them to have my real number in there phone just in case they made a key stroke error. That person has the caller ID and does not accept blavked calls. The problem with that is when it says call back or... ENTER THE NUMBER YOU ARE CALLING FROM... you can enter any number, and that is what shows on their caller ID.
Basically they cancel each other out,and in some cases you still don't know who is calling you.