I got stamped yesterday
Got to SFO INS by 8:30 AM . Luckily got parking on the street nest to building. I read somewhere on this board to use entrance on sansome street when u go for stamping ( moreover your approval also says sansome street address). there were only 6 people in the line. A security person asked if I have appointment and asked me to show, I shoed the approval notice , she said OK to stand in line. she is checking with everybody in the line. with in 5 minutes entered the building and passed thru security clearance (they will check your Id so have your id\'s ready).
I directly went to 200B 2nd floor. On second floor look for 200B room and on the door you find slot to drop your approval notice. this slot is used for all type of appointments not only for I551 stamp. I put all three approval notices (self,wife and kid). One more guy who also put his approval notice before than me said , he was asked to put approval notice along with passport , photos , EAD and AP\'s if you have. I have put already mine approval in the slot, so I waited for call and give then the passport and all other documents. with in couple of minutes all the notices were taken by some persons. Still they have not started calling people , so we waited about 30 minutes then they started calling one by one and when I was called , she asked our passport,I-94\'s,2 ADIT photos AP\'s EAD\'s and they took Index finger print and signature on a form, for kid they just took fingerprint and asked us to wait. after 15 minutes , they walled our name and showed the passport page with stamp . she told that I can use this stamp for travel and work. Along with stamp it has your name , A# WAC # and expiration date of stamp , generally it is up to 1 year. One other guy who came for stamp asked about what if he changes residence address, INS person told to got to 1st floor and take change of address form.
I was out of INS building by 10:45 AM.
I used courtesy approval only. I also see if you have any H1 stamp in your passport it will stamped as CANCELLED.
Good Luck on your stamping.