about 50:50 here too, where I used to work it was awesome, it was a deisgn agency and all the account handlers and managers were serious totty, we had one room we called the Siren Room cos it was just wall to wall skirt.
I work in IT as a programmer. In programming the ratio is about 70/30 but the overall ratio in the company is about 50/50. In managerial positions the ratio is about 50/50, in testing, support, sales and marketing it's 40/60 to 30/70.
This tells us the obvious: Men are better at technical and gruntwork stuff while women are better at communication and management. Men are best suited to understand complex systems and tend to put a touch of art, emotion and egotism in their work while women are better at communicating and usually get the job done without any personal or emotional commitment.