title: How to implement an alarm with iPhone SDK 4.0
body: <p>I have an idea for a pretty unusual alarm clock fir the iPhone. But as of now I have some thoughts on how to actually implement this. First off: forgetting about background services for now, how would I do the actual timer that fires the alarm etc? A separate thread? Or does the SDK include any nice alarm features I missed? Of cause I need to be as battery efficient as possible. But for now I do no background process.</p>
  
  <p>Please advise me on this as it is a crucial concept of this app, if it will work or not.</p>