Getting lots of exercise makes it easier to fall asleep at night. The ultimate solution, however, is to have a small child.
I can't tell you how many parents I know that complain (sometimes bitterly) about how early their kids wake them up, and I find out they put the kid in bed at 7pm. Or 6pm, even.
My wife works best in the morning (and I work just fine whenever), so we play with our almost-2-year-old in the evenings and she generally goes to sleep at 11pm or sometimes later, then wakes up normally about 10am. She's never had a bedtime earlier than 10pm.
I don't know about every other parent (and how this would fit in with life) but this works great for us. We can go out to dinner and/or see friends in the evening when we want to (we take her along), we get lots done in the morning, and she gets her sleep.
Is there some other factor I'm missing? Why, when a child wakes up at 5:30am, is it not automatic for the parents to think "we're putting her to bed 2 hours too early"?
A possible enabler, now that I think about it -- we have great shutters on our windows, so it's dark until we open them.