My ears, three times at the bottom and once at the top, and my tongue. That's enough for me! Many of my friends have numerous facial and bodily piercings. One of my friends has 21, namely, twice in her eyebrows; 11 in her ears; 3 in her lip; both nipples; her tongue; her belly button and her you-know-where.
I see them as just a different style of dress, or make up. As with dress and make up I also believe that there is a time and a place for certain styles. Job interviews for example, even the most decorated face can be toned down for. Another good friend of mine removes her piercings or replaces them with clear plastic ones, for the same reason she tones down her brightly coloured hair. Why? Well because they are a personal expression of your own fashion choices, and basically you are more likely to be accepted in society if you follow uniformed suit...which is probably why these pierced rebels put them selves through the pain and risk of infection in the first place!
Below is a link to a site advising on the basics of piercings.