What kind of phone are you trying to activate? Is there a phone currently active on the line you are trying to activate the new phone on? Is the phone you are trying to activate still active on another line?
A few more details will help us to help you...
You can always call customer service (800-922--0204) from another phone and they can tell you exactly why it won't activate, or get it activated for you. Oh, and to answer your original question, activation should only take a matter of minutes - after you go through the proper steps and the generic music plays for 30 sec to a minute, you get a screen or voice that says activation successful or "Your phone is now activated".
Message was edited by: SuzyQ