iPhone OS 4.0 Basics
Apple today unveiled its plans for the iPhone OS 4.0 software update. The update will ship this summer for the iPhone and the iPod Touch, and in the fall for the iPad.
Apple said the update will include more than 100 new user features for iPhone and iPod Touch owners, including playlist creation, 5x digital zoom in the camera app, tap-to-focus for video, auto photo-geotagging, the addition of Places functionality, the ability to change the Home screen wallpaper, improved spell-checking, and support for Bluetooth keyboards. Many of these functions are already available on the Apple iPad.
Additionally, developers will have access to a new software development kit (SDK) that offers over 1500 new APIs to create new apps for the Apple hardware. A developer beta is available now.
All photos: Courtesy of Macworld
Folders and Game Center

The new OS will allow you organize your iPhone apps in folders for easy access. These folders can also be placed in the dock, making organization a lot easier.
If you drag one app icon onto another, a new folder is automatically created. The folder is automatically given a name based on the App Store category of that app, such as “Games,” which the user can easily rename.
Using folders, users can now organize and access more 2,000 apps on their iPhone. Users can also create and manage iPhone folders on their Mac or PC using iTunes 9.2, according to Apple.
In today’s announcement, Jobs also touted the new Game Center, which would be an Xbox Live or PSN of the iPhone community.
The functionality will allow developers to tap into a centralized network where gamers can play against each other. Apple says the functionality will be available later this year.
Multitasking: Navigating Through Open Tasks

Perhaps the most long-awaited iPhone feature, multitasking capability comes to Apple devices with OS 4.0.
As with copy-and-paste, Jobs acknowledged that Apple wasn’t the first to implement multitasking, but he insisted that Apple has done it best by coming up with a way that doesn’t degrade performance and battery life.
In order to switch applications, users double-click the Home button, which summons a dock-like window showing all running applications; tap on an app to switch to it.
For instance, if you’re playing a game it will pause when you switch to another task, and you’ll be able to resume right where you left off when you switch back.
By default the dock shows you four running applications, but if you have more running at one time, you can swipe left to see the rest of them.
iBooks Coming to the iPhone

iBooks on iPhone
In a borrowed feature from the iPad, Apple will make iBooks available to the iPhone in iPhone OS 4.0. It’s a smaller version of the iPad app, but allows the same features, including purchasing from the iBookstore.
And you’ll be able to sync your place and bookmarks between multiple devices: leave off reading a book on your iPad, and you can start reading it in the same place on your iPhone.
Apple Software Developers Can Go To Work Immediately

Apple today released a beta version of the iPhone 0S 4.0 software to members of its iPhone Developer Program.
The beta release includes an updated Software Development Kit (SDK) with over 1,500 new Application Programming Interfaces (APIs). Developers can start testing the preview immediately, and start developing using the APIs now.
iAd: Apple’s Built-In Advertising System for the iPhone OS

As was widely rumored, Apple announced its own built-in advertising system for the iPhone OS, called iAd.
Developers to incorporate ads into their application and use both video and interactive elements without taking users out of the current application. The system is built entirely on HTML5.