What's New in iOS 5
iOS 5 might be the most popular version of Apple's mobile OS yet. When Apple released it as a digital download through iTunes on Oct. 12 the heavy demand almost crashed Apple's servers.
Available for the iPhone 3GS, iPhone 4, iPhone 4S, and all iPads, this update includes more than 200 enhancements for a reasonable price--it's free. This visual tour focuses on 11 major enhancements and four new apps introduced with iOS 5.
Twitter is integrated in iOS 5. You set it up in the Settings app and it will even update your contacts for you. However, the feature only tells you how many contacts were updated--it doesn't show you a list of them. If you don't already have a Twitter app you can download it directly from the Settings app.