You should really have one of those!
Bringing your kids to your place of work lets them know how interesting (or how boring) your job is. It helps them see what keeps you away for hours. It makes them understand a little about adulthood. It lets them appreciate the concept of 'work' and 'responsibility'. And --it allows them to bond with you like never before.
Sounds cool? Before you jump on the next bus toting your laptop and your child, you have to plan the experience first. Choose a day when you don't have a lot to do at the office. That once-in-a-blue-moon stress-free day should be perfect.
'Don't touch anything.', 'Be quiet.', 'Stop running around.', 'Just sit in a corner.' You do have to watch them closely, but take it easy and let them explore your world for once.
(and your friendlier colleagues) should be open to help them learn.
But at the end of the day, when your children tell you that all they want when they grow up is to be like YOU ... it'll be far more rewarding than any other day at the office. I can tell you that.