i'm from the US. i believe US citizens can stay up to 30 days. you need to have your flight itinerary with you when you go to the vietnamese consulate (or provide such to the visa service you are using).

for some reason, my visa was only good for 14 days. i'm assuming that was because my trip was fairly short and they didn't feel the need to go 30.

i got mine in hong kong. it takes a couple days and the cost is 300HK. i paid 500HK and got express service and it was ready in 15 minutes (after i waited 15 minutes to get to the window). the consulate is in wan chai and it was easy to get there from the wan chai MTR station. maybe a five minute walk. opened at 9am. and it was a busy place.

my buddy got his in san francisco. not sure on the fee but i do know it was not next day service, took an extra day (has always been next day for me when i've obtained the thai 60 day tourist visa). not sure if express service is available in SF but would guess that it is.

no consulate in los angeles which is where i was hanging for a bit prior to my trip. i was there because the thai consulate is there and that was my main destination.

i got my last couple of visas to vietnam in bkk. most travel agencies can do it for you. i paid 2,500THB for the 30 day visa. just need a passport picture, the form (they have at travel agency), and the money. it took four or five days to get it. if you need a quick turnaround, it was another 1,000THB or so.

i also learned that you can extend the visa once you are in the country. at least two more 30 day visas are possible. i didn't ask about the cost though. the extension can be done at any travel agency.

got another visa for vietnam. i went to the vietnam consulate in BKK myself this time. very quick and easy. get off at ploen chit BTS, follow signs to wireless road. elevated walkways take you right to wireless road. easy walk, less than 5 minutes and you are there.

paid 2500thb visa fee and picked up my passport the following day after 3:30pm.

zin jow (hello in vietnamese)
to enter vietnam must obtain visa in advance as there's no visa-on-arrival available at airports & border crossings.

i got my visa in phnon penh at a visa service offered by travel agency / hotel. didnt need to submit application, photo, onward tkt. just handed over passport & 35usd. took only 1 day to get visa.

entered vietnam by land via Prek Chek - Ha Tien, a relatively new border crossing. no lines, no wait.

zoner,

i haven't verified this personally but i think you can apply for a visa over the internet and then get it "on arrival". another member brought this up in another thread.

for this visit, i got my visa via online service. $40 for express, 24 hr service. $20 for regular service. then you also pay $25 upon arrival. so a total of $65 for the express service.

you do have to wait about 30 minutes for the visa to be added to your passport once you get to the sgn airport. one tip, be sure to download the arrival form from the internet and fill it out before arrival. many of the people waiting for the visa on arrival did not do this and that put them in the back of the line. there were probably 25 people from my flight waiting for visas. maybe 5 of us had filled the form out beforehand. still took 30 minutes before they handed back the first passport.