XD, ^^, ^__^, ^.^, ~_^, etc. etc. etc... and people will think I'm a girl.
Is that the trick? I'm getting pretty damn tired of being mistaken for a man. No offense to men, but I find it insulting for some reason.
The word "usedbooks" can be used by a guy. Its a gender-neutral name but you'd be assumed as a "guy" by default.
It would help changing your avatar into something that looks more like the cliche anime oh-so-kawaii anime girls. It may annoy you but that may do the trick.
If you hate stuff that has to do with anime and manga, then put a realistic woman face in your avatar. :)