Just arrived back from Laos so this is as up to date as it gets.
When flying into Vientiane on an International flight the FA's will give you two forms - Visa Application and Customs Declaration. To save time complete these before you land.
In the arrival hall you will see the Visa desk to your right, just beyond the large table on which those who didn't fill in the forms on the aircraft are scribbling like mad so not to be at the back of the queue.
Join the first queue and present your application form, passport and photos. [Note - the form says 3 photos, we took 2 and were given 1 back ! Also if you have forgot to bring any they will snap you there for a $]
What you will notice is that you are greeted with a smile - this is Laos!
You are then directed to the second queue where you wait whilst your Visa is processed and are called forward to pay your fee (varies from country to country and is currently $35 for the UK)and collect your passport.
You then go through passport control (another smile)collect your luggage and pass through Customs ,handing in your Declaration Form. More smiles.
Enjoy Laos before it changes - it is like no where else in SE Asia.