How to disable voicemail on AT&T (with an iPhone).
First up, you're going to have to call AT&T. That sucks, I know, but from what I learned it appears that iPhone voicemail is bound to your data plan, so it can't be easily removed with a mobile dial code (en.wikipedia.org/wiki/Mobile_dial_code ).
Important note for iPhone users:
If you have one of the old school $30 unlimited iPhone data plans, take care that the rep you're talking to doesn't take this opportunity to switch you to one of the new plans; s/he will be effectively removing your data plan and adding it back without visual voicemail, and it would be very easy for them to accidentally add your plan back as the new $25 / 2GB plan.
Here's how to start:
-At the main menu dial 3 for help with voicemail
-Dial 0 to speak with CSR regarding voicemail
-Request to have your voicemail disabled
Now that your AT&T voicemail is disabled, what you can expect when someone calls you:
-You let it ring: your phone will now ring for a while longer than usual (I've been seeing up to a minute). Eventually it will stop trying and play a message for the caller that says (in both English, then Spanish), "The wireless customer you are calling is not available, please try again later." Awww yeah.
-You decline the call: no message is played and the call is immediately terminated. This may make the caller feel like their call was dropped and call again, so I'd advise you wait a few seconds before declining the call instead of doing so immediately.
I will say, however, that PhoneTag's transcription is really, really good. I use PhoneTag for our home phone. I'd drop the home phone in a heartbeat but we need it for the alarm system and, for some reason, my wife likes it.
You could always go the route of some of my less tech-savvy relatives and just make your outgoing voicemail greeting something along the lines of, "don't bother leaving a message. i do not check my voicemail." they don't check it because they don't know how rather than they don't want to.