Southeast Asia Visas

Every country has different visa regulations - how long you can stay, the price for the visa and the extension requirements are different for each country and change from time to time. Many countries in Southeast Asia allow for a Visa on Arrival - which means you can show up at the airport and get your Visa there. However, some countries require you to apply for a Visa at an Embassy first. Also keep in mind that a Visa on Arrival will generally be for a shorter period of time (1 month or less). If you need to stay for a longer time then you can either apply for a longer Visa at an Embassy before you arrive, or else check if you can apply for a Visa extension once in the country.

Some Visa tips things to keep in mind:

If you plan to enter the country more than once (maybe to take a quick hop over to a nearby country and back) then you will need a multiple-entry visa.
Some countries (such as Vietnam) require that you list you entry and exit points for each of your visas, which can make changing your travel plans difficult.
The type of Visa (and your allowed length of stay) may be different if you arrive by air or by land. Thailand, for example, grants a 30 day visa if you arrive by air, but only a 15 day visa if you enter by an overland crossing.
Some Visas or activated on entry and some are activated on issue. If you get a 1-month Visa that is activated on issue and don't arrive in the country for three weeks, then you will only be able to stay for 1 week.

Cambodia: 30 day Visa on arrival for most nationalities
East Timor:
Indonesia: 60 day Visa on arrival for most nationalities
Laos: 30 day Visa on arrival for most nationalities
Malaysia: 60 day Visa for most western nationals, 30 days for US
Myanmar:
Philippines:
Singapore:
Thailand:
Vietnam: