I made an appointment to get extra pages in my US Passport.

For people who have done this before, how does it work? Is the process completed on the same day? I see that they want me to fill out a form and that there's an American address on there. However, since I'm actually going to the Embassy to do this in a foreign country can the procedure be completed there? I'm hoping to get the passport pages on the same day and then make a trip to Laos and apply for a double entry.

They will add the pages while you wait for it to be done at the embassy.

Info here: http://bangkok.usembassy.gov/add_extra_visa_pages_us_passport.html

Reports indicate that effective 1 Jan 2016 US citizens will not be able to have pages added. I have a friend that was just issued a new passport and when he picked it up he inquired about extra pages because he travels a lot. They put in two sets of extra pages for $82. It's worth asking if you travel a lot.

Since the prices of new pages and a new passport are not to far different, it is worthwhile to consider getting a new passport good for 10 years than to add pages that will last far longer than the expiry of the passport.

Reports indicate that effective 1 Jan 2016 US citizens will not be able to have pages added.

That's correct. I received an e-mail from the embassy stating such.