The Alarm Clock version 1.6.1 is a minor update that re-enables the proximity detection feature that was removed from an earlier version. The iPhone SDK 3.0 now officially supports the use of the proximity detector in third party iPhone OS applications.
If you dislike the iPhone glowing even with the brightness level set to its lowest value then switch Proximity Sensing in advanced options to on and set the phone upside down on your nightstand. This will turn the display completely off until you pick up the phone.
