I'm kind of in the same boat as you. I have a three year old and a ten month old. Luckily, I've gotten them both to take an afternoon nap at the same time. During that hour and a half, I do most of my writing research and plan out my article/post. At night, I take an hour or so to actually write what I need to write. Then I spend an hour with DH -if he isn't busy surfing ebay by then!
Good luck! And thanks for asking this question, I got a lot out of the responses as well!