How can I show a single block only if the user is on iOS? I have a Picture content type that allows users to upload picture files, something that iOS does not support.  Since Apple in 2012 can't support something my first computer running Netscape Navigator was able to do in the early 1990s, I'd like to give a message to iOS users that they will have to e-mail me the photos instead.

I installed the Browscap module but it only detects the user agent; it doesn't do anything by itself.  On Drupal 6 I used Mobile Tools, but it has yet to see a stable release for D7.

I only want to show a single block on a single content type to iOS users, so I'm looking for the simplest possible solution.
My dull ax dealing with this same issue boils down to a little module helper function along the lines of:

function _MODULE_is_iOS() {
  if (strpos($_SERVER['HTTP_USER_AGENT'],'iPad')  !== FALSE || 
      strpos($_SERVER['HTTP_USER_AGENT'],'iPhone')!== FALSE || 
      strpos($_SERVER['HTTP_USER_AGENT'],'iPod')  !== FALSE) {
    return TRUE;
  } else {
    return FALSE;
  }
}


and then using that within my block hooks, eg,

if (_MODULE_is_iOS()) {
   $block['content']= // whatever I need for iOS
}


or from within the Block Admin PHP visibility area if in a pinch.