This is certainly something I don't have to tell the women in the game group I'm in, but now according to a "reputable" survey of people in the UK there is empirical evidence. Or at least that's what the Wired blog network says:
Female Gamers Have More Sex
Perhaps even more promising for gamers is the fact that many of the women that we interviewed who have only recently started playing games said that they now have sex more often than before.
So if you haven't all ready, get out your joy sticks now ladies.