What' the best way to save iphone app setting?

I'd like to allow user to change the setting of app. But I am not sure where shall I save the configuration.

Is there any local space allocated for app?

Thanks.

From stackoverflow BlueDolphin

• You should use the NSUserDefaults class for storing settings. It's all documented.

  From Ben Gottlieb

• Have a look at this example app.

  From Dan

• Thanks, it really helps!

  From BlueDolphin