Someone has to try this one!

 A free Android app called SleepBot can lend a diagnostic hand. Just place your smartphone next to your pillow, and the app will track your movements and sounds through the night to figure out how long you slept. (On a slightly creepy note, the app can even record audio so you can play back your snores and sleep-talking.) When it’s time for you to wake up, SleepBot tries to wait until you’re in a light-sleep phase of your sleep cycle before sounding the alarm.