To finish up my stay in Vietnam I decided to take a Mekong Delta tour during three days ending in Cambodia. These tours are very common in Saigon where you go for three days (two nights) and then you come back to Saigon. Anywhere you walk in Saigon you’ll find a travel agency where they advertise them. I don’t know if there are different types of tours, but I would generally avoid them if you are thinking of going yourself.