One of the most effective alarm clocks is to have children. You are guaranteed to be woken up bright and early. Well early, not so sure about the bright part.<p>Joking apart, having children does force you into a strict daily rhythm. They respond so well to doing the same thing, at the same time, and in the same order.<p>I always used to have poor sleep habits. Those habits have now been beaten out of me!<p>My point is that having a fastidious approach to sleep, and a strict sleep pattern means that you pretty much don't need an alarm clock. My children can't tell the time yet, but their internal body clocks are pretty accurate. Slowly I'm starting to trust my own internal clock as well.