I don?t advertise the fact that I?m a girl, but I don?t hide it either. More than a decade online has taught me a few harsh lessons, the main one being; If you don?t want to be approached, then don?t be accessible.
It?s actually a tough thing to master, giving off that vibe. Especially in a social setting like WoW, where almost all raiding guilds require ventrilo.
You can be friendly and nice and still have that line drawn in the sand, though there are idiots who will flat out ignore all of the ?I?m not interested? messages right up to the point of you actually reporting them for harassment.
Mostly I just continue on doing my thing, make it clear that I?m not available when guys ask (doing a fair chunk of my gaming with my partner by my side is a pretty good deterrent) and if some new boy asks ?OMG are you a GIRL!?? over vent I just tell them I?m a guy with a very girly voice. *shrug*