How can I block my number?

[Ginnungagap]

How can I block my number? 

[WongTong · Accepted solution]

Simply dial "#31#" followed by  the 10-digit phone number you wish to call if you have an HSPA device (using a sim) or *67 if you're using a CDMA device (older technology without sim card)

On most HSPA devices, you can also change outgoing caller ID settings under Call Settings>Restrict My Identity (Settings will vary with each phone)