Since a lot of social media users are using Smartphones – and the iPhone in particular – to keep in touch with their social circles and network contacts, we thought it would be useful for people to have a list of the new and upgraded features in the newest version of the iPhone operating system: iPhone OS4.

In addition to some eagerly-anticipated features like multi-tasking, home screen wallpaper and folders for organizing app icons, there are a host of other changes that aim to make iPhone more user-friendly.

Here’s a list of changes/additions copied from the installation screen when upgrading to OS4:

This update contains over 100 new features, including the following:

• Multitasking support for third-party apps*
- Multitasking user interface to quickly move between apps
- Support for audio apps to play in the background
- VoIP apps can receive and maintain calls in the background or when device is asleep
- Apps can monitor location and take action while running in the background
- Alerts and messages can be pushed to apps using push and local notifications
- Apps can complete tasks in the background

• Folders to Better Organize and Access Apps

• Home Screen Wallpaper*

• Mail Improvements
- Unified inbox to view emails from all accounts in one place
- Fast inbox switching to quickly switch between different email accounts
- Threaded messages to view multiple emails from the same conversation
- Attachments can be opened with compatible third-party apps
- Search results can now be filed or deleted
- Option to select size of photo attachments
- Messages in the Outbox can be edited or deleted

• Support for iBooks and iBookstore (available from the App Store)

• Photo and Camera Improvements
- 5x digital zoom when taking a photo**
- Tap to focus during video recording**
- Ability to sync Faces from iPhoto
- Geo-tagged photos appear on a map in Photos

• Ability to Create and Edit Playlists on Device

• Calendar invitations can be sent and accepted wirelessly with supported CalDAV servers

• Support for MobileMe Calendar Sharing

• Suggestions and recent searches appear during a web search

• Searchable SMS/MMS messages**

• Spotlight search can be continued on web and Wikipedia

• Enhanced location privacy
- New Location Services icon in the status bar
- Indication of which apps have requested your location in the last 24 hours
- Location Services can be toggled on or off for individual apps

• Automatic Spellcheck

• Support for Bluetooth keyboards*

• iPod out to navigate music, podcasts and audiobooks through an iPod interface with compatible cars

• Support for iTunes gifting of apps

• Wireless notes syncing with IMAP-based mail accounts

• Persistent WiFi connection to receive push notifications*

• New setting for turning on/off cellular data only**

• Option to display the character count while composing new SMS/MMS**

• Visual Voicemail messages can be kept locally even if they have been deleted from the server**

• Control to lock portrait orientation*

• Audio playback controls for iPod and third-party audio apps*

• New languages, dictionaries and keyboards

• Accessibility enhancements*

• Bluetooth improvements

• Better data protection using the device passcode as an encryption key* (Requires full restore.)

• Support for third-party Mobile Device Management Solutions

• Enables wireless distribution of enterprise applications

• Exchange Server 2010 compatibility

• Support for multiple Exchange ActiveSync accounts

• Support for Juniper Junos Pulse and Cisco AnyConnect SSL VPN apps (available from the App Store)

• More than 1,500 new developer APIs

• Bug fixes