The first thing that comes to mind is to be flexible in scheduling classes, even if they've always been taught at a certain time or in a certain way. That can make a huge difference, not just for parents but for people who have any outside priorities or who simply know that they teach best at certain times of the day. This can also generate a discussion of dislikes: given the choice of more preps, teaching at an undesirable time, or teaching more credits, what do individuals prefer?

In a similar vein, schools can let faculty teach a summer class in place of one of their regular semester classes. I do know schools that will do this for new parents, but ideally it would be an option for everyone. (Are there any schools that allow this in general? I'd love to hear of them!)

Allow people to spend time out of the office (a few afternoons a week, or one day a week) instead of being available 9-5 (or 7-3) every day. This could mean interruption-free time for research, or it could mean working at home. To my mind, it could also mean going to the zoo with the kids, as long as the time was made up elsewhere and faculty were still normally available to students (during office hours and appointments, for example).

Finally, provide laptop computers in lieu of desktops upon request. They can be great for working at home and can also be good for research if your work takes you into the libraries.