On the face of it, this is a fairly small thing. But if you are addicted to Twitter, the arrival of 'push' mentions for the Apple iPhone is something to really shout about.Yes, never miss any mention of your name - you'll get a 'ping' and message on your homescreen saying who said it and what they're saying, presuming your phone is on. All you need to do is download the latest version of Twitter for iPhone, which you can download as of today from the App Store. It's free of course.In addition to mentions, Twitter is also bringing push notifications for messages to Twitter for iPhone, as they have already done with SMS and Twitter for Blackberry. Good news for Apple customers, not really for other platforms, although Twitter claims it is 'working hard to introduce this feature to Twitter for Android and Twitter for Windows Phone soon'.Don't want it on your iPhone? Just go in the settings and set to 'off'. It's that easy.