title: iPhone 4: when to save data?
body: <p>I have an app (a game) which saves data: game state, high scores, achievements, etc.  Currently the app delegate does this on <code>applicationWillTerminate:</code>.  After playing around with iPhone 4 for a bit, it seems that applications pretty much never terminate: they just run in the background forever, unless the user goes out of their way to quit them, or restart the phone.</p>
  
  <p>So my question is, should I find another place to save my data, and if so, when?</p>