A very high portion of my friends cannot be connected via the number stored in my mobile phone. They changed their mobile phone number, just to use the Unicom iPhone. They consistently share their new mobile phone with 186 at the beginning of the numbers with me. For more, I simply got "The number you dialed has been out of service" message when I try to reach people.
Will it be significant that a new communication tool, or even just a new client device like iPhone dramatically shift the social interaction? Think about fax number. The impact of the iPhone 4 wave for me in China is, it cuts my friend connections effectively.