I agree - set aside some space for him to be free, like his own room - just put a gate up!
A playpen is going to severely limit not only his mobility (which may seem like a good option) but also his opportunity to develop his army crawl into hands-and-knees crawling - which is actually ESSENTIAL for brain development, and for good vision, as both kinds of crawling will give him lots of opportunity for his eyes to learn to focus, and the freedom to move around at least one room will help him learn to map out spaces. (Check out
http://www.childbrain.org for a whole message board about this kind of stuff!
Natalie's been crawling around since Heaven knows when, on her hands and knees since about 5 months and now she's almost 8 months and CRUISING. :shock: Yeah, I had to do a LOT of childproofing, and it's a hassle keeping her out of Josie's stuff (and DH's and mine), but we know that if it's within her reach she'll get into it, so we give her some space that's hers alone or keep her in a room with us with toys for her to crawl to and play with, and I think that's why she's moving along so quickly. And at this rate, at a time when most kids are starting to pull up on stuff, she'll be walking and we can leave curtains hanging again!
(we hope! LOL :lol:)
You're going to have to childproof to this degree at some point anyway - why not just do it now? Better all 'round. And enjoy your precocious little one!!!