We did this wonderful trip in January 2012 and did the VOA. Here's what I remember...We were very diligent and had the info forms all filled out (many people had not pre-filled them out), our passport-sized photos and the letter (we had it emailed, so, basically it was a copy when we printed it off). We rushed off the plane (were in the first row) in Hanoi, and got in line at one side of the booth. There were at least 8 uniformed officials in the booth, but no one seemed to be doing very much. At last someone took our passports and my application, but not my husband's forms/photos and sent us around to the line on the other side of the booth. I kept trying to give them his application, but they didn't want it. After about 15 minutes we were summoned up, and HERE'S THE IMPORTANT PART, they collected our $45 each in US cash, and gave us our passports. Mine had the visa, his didn't. We pointed it out, they slapped a visa in his, and we were off!!! We're still laughing about that one! A number of people did not have the $45 cash, and I am not quite sure what they did, so be sure to have the correct change for whatever the fee is now.
And, by the way, you would think by that time our luggage would be endessly spinning around on the carousel...not so. Not one piece had come down yet.