AT&T charges for it, if you're jailbroken there is a Cydia app for it called 'blacklist'.
Tap on Settings, scroll down to "Phone" (or "Messages" if you want to block texts, too) and tap on "Blocked" to enter the number you want to block.
You call your servize provider and tell them to block that number that you want blocked
IPhone
Massie Block's phone in the "Clique" series is described as a pink rhinestone-encrusted Sidekick.
By knowing my phone number. Then by using a phone to call me.
There are a number of ways to block phone number depending on what type of phone you have. Usually your manual will give the specific code to do so.
According to the books she first has a Motorola razr and then she gets an iPhone.
Depends where you are?O2 users in the UK just can't!This guy has a campaign to get this added as a featurehttp://www.guardianforce.co.uk/2009/gadgets-tech/iphone-the-campaign/You'll need to go to the Apple site to get it added (Follow the links)
To block a specific phone number from texting you on a PagePlus phone, you can have the provider disable SMS on your phone. There is currently no way that you can block a specific number from calling you on a PagePlus phone, but if you report the unwanted calls to the FCC, you may find that the calls stop.
Contact At&t and they will block it for you.
The phone number of the Baker Block Museum is: 850-537-5714.
The phone number of the Block Island Historical Society is: 401-466-2481.