Blocking Phone Calls on the iPhone

Question

Anyone have a method to
block incoming phone calls
from arbitrary numbers or
swaths of numbers to an
Apple iPhone 3g?
Example: block all calls from
area code 951... block all from
951-123-4567, block all
that come in from 951-123-*,
etc.
Lightwave on the Palm Treo
can do this, easily. (I am pretty
new to the Apple iPhone so
pardon the newbie approach.)
Stuart

Answer 1

As with a landline, I believe cell phone numbers can be used for telemarketing purposes by a company you have done business with if you provide your cell phone number to the company when purchasing merchandise, etc.
I doubt many cell phone carriers are overly concerned about losing market share - with each other maybe, but not losing market share to landlines. AT&T's residential landline business has been gradually dropping for years with a significant drop indicated with their most recent quarterly report, which is the same for all landline providers. I use my personal cell phone in place of a landline, and I've been doing this for the last 5 years or so, which has been a growing trend.
Telemarketers are probably more respectful of Federal law in this regard with a Federal do not call registry for landlines and cell phone numbers they must respect or face prosecution or fines by the Federal government. Regardless, there is a Federal do not call registry, which everyone with a landline or cell phone number should use if they want to prevent or minimize telemarketing calls, and be careful or aware before giving out their phone number.