Truth in Caller ID Act of 2007 – Amends the Communications Act of 1934 to make it unlawful for any person in the United States, in connection with any telecommunications service or Internet protocol (IP)-enabled voice service, to cause any caller identification (ID) service to transmit misleading or inaccurate caller ID information, unless such transmission is exempted in connection with: (1) authorized activities of law enforcement agencies; or (2) a court order specifically authorizing the use of caller ID manipulation.
*and theres new legislation their trying to pass too with even more strict guidlines*
id stick with the apps and spoof cards for now... actually modding your phone to do so permanently may get you into trouble
EDIT good little write up
http://www.theprivacyguy.com/2007/06...-made-illegal/ also where i got the truth act info from