I went VOA at www.vietnamvisacheap.net – 3mth visa.
Paid $20 upfront (debit card) for my approval letter which arrived via email within 3 days ready for printing, plus a link to download the form that you have to fill on arrival – fill it in to save time! after 3 days I have a cheap Vietnam visa
On arrival (Saturday just gone) went to the window, far left of immigration. Handed over letter, filled in form and one photo + passport. After a short time, name called and asked to pay $50 to cashier. One passport with visa returned. Then had to go through the immigration desks (can’t really see the point for getting into another queue but who am I to say otherwise) Far cheaper than applying back home for the same visa and no problem. Still ended up waiting for my baggage to appear on the conveyor!
As previously mentioned, it does pay to check what documents etc are required before visiting any country. The UK is very strict and you wouldn’t even get on an aircraft without the correct paperwork. The airline would only have the job of returning you. The fun part is I can nigh on travel the whole of Europe without having to show my passport to any official and yet to get back across the English channel to England I have to, on both outward and inward bound!