Lights out: Do your kids have a set bedtime routine?

Sasha and Malia Obama may be having a blast on their new play structure (which sits on sand in plain view of the Oval Office - how cool is that?). But one thing is certain: Even if their fun lasts well into dusk, they'll still have to go to bed at a set time: 8 pm.

Over at The New York Times "Well" blog, Tara Parker Pope is leading a discussion about bedtime routines for kids. While most parents know that setting a regular sleep schedule for their kids is a good thing, how many moms and dads actually stick to those schedules?

Personally, we have set bedtime for our kids but it's definitely flexible if we've attended a special event. It's just something we started when the kids were babies and have stuck to the routine, but adjusted the time the lights must be out. The kids seem to dig it, so there's no reason to stray from it. We also can see the difference in our kids' behavior when they get less sleep on those days when they are in bed later than normal.

What about you? Do you stick to some sort of bedtime routine? What time do they go to bed (share their age, too) and when did you stop using a set bedtime?