A number of geek girls have responded on this topic. For those of you still in school, I just want you to know that not all IT shops obey the stereotypes that we've seen mentioned on this topic.
I work at a S&P 500 utility in Florida. We have an in-house IT staff of several hundred. I'd say that roughly 30-40% are female. Half of the department heads are female, and our acting CIO is female. And these women aren't stuck in the touchy-feely areas either. We have female C programmers, Unix admins, Oracle DBAs, web programmers, etc., etc. Right now my own team doesn't have any females, but that's unusual. At one point it was about 70% female.
So what's the point? Just that these notions that women "can't do" the techie stuff are baloney. Some of the sharpest programmers I've known are women.
As to "encouraging" women to go into CS, I have mixed feelings about that. I'm not sure that -anyone- should be "encouraged" to go into CS. It's a very difficult field. Not because of the smarts required; plenty of fields require that. No, because of the commitment and dedication required. The field moves so fast; learning is constant. I think if you're not at least somewhat "driven" to be constantly learning about new technology, on your own time, then this is not the field for you. I've seen a number of young people burn out and leave the field (or worse, stay on and just become obsolete and incompetent) once they realized that graduating from college wasn't the end, but rather the beginning of their learning.
But if you're driven, whether male or female, hang in there, because we need you! :)