Allowing new moms to bring the baby to work is a growing trend, particularly in small firms. The Boston Globe recently ran a story featuring a few firms that do offer this option (see here). There are many pros and cons to allowing babies to come to work, and it certainly won't work out in all kinds of companies. But, kudos to those companies that can make it work.
The Boston Globe article also mentions some companies that allow parents to bring their kids to work on an occasional basis. If school is closed or a nanny calls off at the last minute, parents are often stuck in a dliemma where their only option is to take the day off. A company policy that allows the child to tag along with mom or dad for a day can take some stress off parents and also reduce unnecessary absences. An older child can be set-up in a conference room to do homework or watch a video. A toddler can find some amusement playing on the floor by mom or dad's desk.
Obviously a parent won't be as productive with a chlid along at work, but they will be more productive than if they stayed home. And of course, such a policy won't work in every company. But, a few enlightened companies that allow an occasional child in the office create a step in the direction of a world where family friendly work exists.