The best way to know Vietnamese girls is to live in Vietnam for a period of time, and the best place to live is near an institution of higher learning with Chinese major. There will be many girls who want to chat with China people, because they want to improve their Chinese, and you can just learn some basic Vietnamese. Vietnamese girls like mature men who are masculine. It would be better if they were more handsome and rich. In addition, I need to tell you that Vietnamese people don't like to use MSN and QQ, and Skype is basically not used. Their most commonly used chat tool is Yahoo! Therefore, if you want to meet Vietnamese girls online, you'd better use Yahoo! Looking for friends.