I have a long standing (going on a couple months now) issue with someone in Portland calling my cell phone when she actually means to be calling her mom or something. Anyway, she’s probably done this a couple dozen times in the last 2 months, and a bit ago, I decided to actually do something about it, since ATT doesn’t seem to have any free way to keep this from happening.
Turns out, I’m not the first one to have this issue. And after finding this post, I was easily able to add the silent ringtone, and then add the number to a contact with that custom “ring”. And now, if this happens any more with another number, you can just assign them to that contact as well, and they’re gone! Sure, you can still “see” the incoming call, but you don’t actually have to hear/feel it (with iOS 5+, you can assign no vibration to certain contacts as well).
Luckily the person isn’t dumb enough to leave me a message. =/