It is possible to get a visa through a travel agent, particularly Visa on Arrival. This is a much better and easier way to deal with all visa matters than to do it on your own.
The agent will need passport details in advance and will send a confirmation for the visa to be issued at your airport of arrival in Vietnam.
In Asia, there are several places to pick up Vietnam Visa: Cambodia (it costs around 30 USD), Thailand (Bangkok in particular), and Vietnam, of course.
For more information about getting visa through agent, or to apply for a Vietnam visa, please click here http://www.vietnam-visa.com