A while back I stumbled upon the Sleep Cycle alarm clock. The idea of the app is that it monitors your sleep pattern and wakes you during a half hour window as you are in a period of lighter sleep.
About a week ago, I started actively using Sleep Cycle. With a 4 month old baby in the room, sleep patterns are far from ideal. Although I’ve not benefited from the refreshed feeling that would come when waking during the optimum period, it has become quite an addiction checking out the stats graphs each morning.