No.
please give your number
You can change your number in your settings. Go to your settings and press phone. Then press my number. You can now change your number.
To change the sim card on your iPhone simply open it at the back remove the battery and replace your sim card.
You can buy the iphone from apple & put it on whatever network you want to, but you cannot buy it from a phone network & change the network.
i want change my phone number
Contact AT&T if you want to change the name on the contract. Or if you "found" it restore it and change the SIM or take it to AT&T
changing my pin number
gives the people what they want without problem. that's it.
If you never enabled Find My Iphone and want to try to track your iphone using IMEI number this website can do that: iphonetrace.
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.
∞ -- Copy and paste this character if you want to use an infinity symbol on your iPhone. There is no infinity symbol available on the standard iPhone keyboard.
You can add a signature to your emails, via the iPhone 4. Go in to the email settings and you have the option to change from the "sent from my iPhone" to anything you want. This will hen be automatically added to all outgoing emails as your signature.