We have a daughter aged 3 3/4 and a son 7 months. We didn't even consider a playpen for our daughter. Our son can't crawl but can cover an amazing area by shuffling and rolling. I have to admit that neither me or my husband are the tidiest of people and also our daughter also leaves stuff lying around so I'm constantly coming into the living room having left him for five minutes in the middle of the floor to find him in a corner chewing a book! Husband has suggested a playpen but I'm not keen, seems like fencing him in and curbing his developement. I did a 'search' on this site for playpens and no-one seems to have brought up the subject before. What do you think?