Jonathan **************************
@Henrik ****
Onward ticket or return ticket amounts to the same thing.
Its now official policy that you have to show a ticket both in and out of the country, though some consulates might be following that guideline less strictly than others.
In Vientiane, for example, they're less stringent about the ticket *into* Thailand, understanding that most tourists will be getting a taxi to the border and then hopping onto a bus or minivan.
However, even at Vientiane, people have been getting turned away for not having a ticket *out* of Thailand (call that ticket whatever you want, it amounts to the same thing).