iOS5 - The World's Most Advanced Operating System... And even as others try to catch up, the technologies and features built into iOS keep iPhone years ahead.
Amazing Feature 1: "Notification Center - It’s the one place where you’ll see what’s up. iPhone works with your apps to let you know about missed messages, calendar invitations, friend requests, and more. New notifications appear discreetly at the top of your screen. And you can see a summary of recent notifications when you swipe down from the top of any screen."

..."years ahead"?
Shared publicly