title: Class as NSNotification observer?
body: <p>Should it be possible to have a static NSNotification observer (like the code below)? I'm having some problems, and I think it may be due to my singleton class structure.</p>
  
  <p>I don't always have a class instance around to listen to the notifications, but the static properties of this class stick around for my application's lifecycle.</p>
  
  <pre><code>- (id)init {
      [super init]
  
      [[NSNotificationCenter defaultCenter] addObserver:[self class]
                                               selector:@selector(action:aNotification:)
                                                   name:@"NSSomeNotification"
                                                 object:nil];
      return self;
  }
  
  + (void)action:(NSNotification *)aNotification {
      NSLog( @"Performing action" );
  }
  </code></pre>