http://help.cbp.gov/cgi-bin/customs.cfg/php/enduser/std_adp.php?p_faqid=905
*As a general rule, passports must be valid for six months beyond the date the traveler will exit the U.S.。。。
*Lawful permanent residents (LPRs)。。。 will continue to be able to use their Alien Registration Card (Form I-551), issued by DHS 。。。to apply for entry to the United States.