Good to see I'm not alone! I'm 33 with 2 kids, working on http://www.koonsolo.com in my spare time. I have the advantage that my hobby is my startup: creating games. It's still hard to find the time though. My advice: get plenty of sleep to stay productive. But with a small baby, even this is sometimes hard to get.
Best of success to every spare time entrepreneur daddy! :)
Best of success to every spare time entrepreneur daddy! :)