It's usually part of your plan. Once in a while folk want to know a way around the plan. Are you asking that question since outside of using other than your carrier assigned phone number this is not a phone setting but something done at the carrier.
I have a new cell phone and I need configure forwards calls on it, but the thing is that the options are blocked.
How do I can disable or unblock this area?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic