I was won over by a recent article that said 7.5 hours of sleep wasn't as good as 8 hours, but 8.5 hours was. I started setting my alarm clock for 8 hours from when I go to bed, and I try not to get up until the alarm goes off. It has gone really well; I never feel tired and I can easily stay up for 24 hours if I need to. If you're permanently "maxed out" on sleep debt, you can function, but you can't take on any more debt. If you're always all paid up, then you can function the one time when you need to sleep for three hours and then be up for an entire day. That's my theory, anyway.

(One key to this is not going to bed too early. Sometimes I'm tired in the middle of the day, and then sleep from, say, 6 to midnight. This fucks everything up.)