Other key new elements in 4.0 are:

* Addition of "folders" into which groups of applications can be placed.* iBooks, an electronic book purchase and download service, apparently identical to that offered on the new iPad.* An online "Game Center" similar to Microsoft's Xbox Live community.* A platform that will let advertisers and software developers embed a range of multimedia ads directly into an iPhone 4 application.

Some features remain missing. Apple didn't and (or Java). Apple CEO Steve Jobs suggested that the emergence of the HTML5 standards render proprietary rich application formats unnecessary.

Multi-tasking is being touted as the basis for a range of new capabilities on the iPhone and Touch devices, and in fall of 2010, the as well. A music app such as Pandora can now run in background, when you switch to a different application, instead of stopping as it does now. Likewise, running a VoIP client to take an Internet-based voice call, you can switch to another application, or vice versa, without dropping the call.

These will be available to developers in the form of "services," according to Apple executives, which might suggest that developers won't have unrestricted access to the full range of multi-tasking features in the underlying OS.