The latest edition of the CSTA Voice (Yes, I read it cover to cover every time it comes in and so should you if you are a high school computer science teacher - or teach CS to younger grades) included a link to a program called Girls Get Information Technology that is being run in Florida.

Their vision:

To create a network in Florida that offers girls and young women exciting opportunities to connect and explore the worlds of Science, Technology, Engineering, and Math that lead to rewarding careers and better their lives.

For teachers they  have games and activities (broken down by grades 6-8 and 9-12) They have a set of resources for parents. There is a really long list of resources for girls as well. And of course as you would expect there are games and activities for girls. But you know, some boys may benefit from all this as well. Just don't tell anyone. :-)