iOS 5 lets you sync local calendars (and local contacts) from your desktop PC or Mac via iTunes if you connect the device via a USB cable or Wi-Fi -- or over an Internet connection via a free iCloud account. That way, you can get your Outlook or Address Book contacts into your device easily and even keep them in sync with your iPad, iPhone, or iPod Touch. Server-based contacts (and calendars and email addresses) are of course synced through the relevant server: Exchange, Google, and so on.
Contacts. It's easy to navigate through your contacts in iOS's Contacts app: Jump to names by tapping a letter at the side of the screen, such as "T" to get to people whose last names begin with "T." Or search quickly for someone in the Search field by typing part of the name.
When creating address information, Contacts provides dozens of fields you can use. You can also assign custom ringtones and custom vibrations to each contact. But iOS's Favorites capability is limited; you can designate a person's specific contact info -- say, a phone number or email address -- as a favorite, which puts it in the Favorites list in the iPhone's Phone app (if a phone number) or FaceTime app (if an email address). That's it.
Where iOS falls surprisingly short is in its inability to create groups. It supports email groups created on your computer or available on your server, but you can't create new groups on an iOS device. Also, you can't pick a group in iOS's Mail address fields. Instead, you select a group, then open it up to select just one member, repeating this step to add more names -- a really dumb approach. What you can do in iOS is link contact cards to create virtual groups; for example, if you have separate entries for a couple, you can link their cards so that each person's contact information appears in both of the cards.
Note that iOS does not automatically put Exchange contacts into its Contacts app; you have to add them manually from within an email. This is not a bad thing, as it means that departing employees don't have your entire company contacts database on their mobile device, and it keeps the Contacts app from being filled with contacts a user probably doesn't need.
Social networking. iOS comes with Apple's Messages app for instant networking among friends, but it works only for text messages to other smartphones and, with no SMS charges, to friends who have iOS 5 devices. iOS 5 does integrate Twitter sharing into several core apps, such as Safari, but you have to install the free Twitter app yourself. Other social networking apps, such as Facebook and Google+, are available for free but do not integrate with apps' Share menus. There is no single-view social networking app for iOS as there is for BlackBerry OS 7 and Windows Phone 7.5. If social networking is your primary use of a smartphone, an iPhone is not the right device for you.
Sign up for CIO Asia eNewsletters.