The Thai consulate in Vientiane is going to an online appointment system starting Feb 1st. It is NOT like the one currently running at the thai consulate in Singapore (which has been running for over a year) where you submit documentation and get "pre-approval".
It is ONLY an appointment booking system in Vientiane, BUT it appears they will NOT accept walk up service once this system comes online;
Here is the website;
www.thaivisavientiane.org Here are the information pages: