title: iOS what to do instead of polling for near real-time data?
body: <p>I'm developing an iPhone (and later Android) app that has real-time features, i.e. when one user posts something others will see it (depending on where they are in the app).</p>
  
  <p>When implementing this in iOS one must keep in mind that network activity takes up lots of battery power.</p>
  
  <p>The <a href="http://developer.apple.com/library/ios/#documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/PerformanceTuning/PerformanceTuning.html" rel="nofollow">iOS App Programming Guide</a> says "Connect to external network servers only when needed, and do not poll those servers."</p>
  
  <p>How then is it possible for apps to have near real-time updated information?</p>