The Automated Passport Kiosks at select airports only work for US Passport Holders and those who visited the US once since I believe since 2008. I have used the E Passport machines at SFO,SEA and YVR LAX has them too. They do save time as opposed to filling out the form on the plane you put your Passport under the Barcode Reader and follow the onscreen prompts. First it will ask you to answer the declaration passports, then you will take a picture and then have the option to add additional travelers who are listed under the declaration form.

After this you will take the ticket to the next available agent who will then swipe your passport and you will keep this form until you get your luggage and turn it in just before clearing customs as you will be directed to the Nothing To Declare or Declare Lane.

For International Passengers you will keep the ticket which is your Visa and return it upon checkin for your return flight.