Sleep Cycle is is a nice twist on the standard alarm clock. Using your microphone, it tracks your sleep patterns and wakes you in the lightest phase of sleep so you're not groggy. You set a window during which to be woken (for example, between 7 and 7:30 a.m.), and it figures the best time to pull you out of your slumber. It even lets you tap your phone twice to snooze.