Recently I attended a committee meeting as an 'observer', and I noticed after a while that whenever the committee had to come up with names of people to take on certain positions of responsibility, only names of men were mentioned. When the position of note-taker was discussed, a woman was mentioned. Then the committee went back to discussing more positions of responsibility, and the lists compiled had only the names of men on them.
Although only an observer, I wanted to say something about this, but just as I was deciding on how to jump into the discussion, a man on the committee said "Hey, I just noticed that we only have men on these lists." The others nodded and another man immediately came up with the name of a distinguished female professor. Then someone else thought of another woman. Like magic, qualified and even talented women appeared in the collective consciousness of the committee.
One excellent thing about this is that the man who noticed the lack of women has previously complained to me about how stupid he thinks it is to consider gender as a factor in anything to do with our jobs as science professors. Maybe he still thinks that, maybe he doesn't, but today he spoke up and it made a big difference.