It depends on your definition of things...well of geeks anyway, I think we can agree on what a girl is meant to be.
Anyway. I don't think of myself as a geek but I have been called one, due to my knowledge of films, books, comics and games, but I tend to think of geeks as being obsessive.
But back to the topic at hand, I don't think there are many posers, but being a girl on a game related forum always used to get you instant attention (although there are more girls here now then back when I go here, and one of those turned out to be a guy) and that attention can be pretty enjoyable, especially on a more polite forum such as this one. Some people might get carried away in terms of trying to be liked, and this could be where your posers appear.