New iPhone Operating System - iOS 4

If you have a recent iPhone, you'll want to download Apple's new iOS 4 software update today.

Apple's iOS 4 software promises 100 new features for owners of the iPhone 3GS, released last June, including the ability to multitask, or run more than one app at once. It also lets you take control of the growing inventory of apps by organizing them into folders.

The software is being released today in advance of Thursday's 7 a.m. launch of the new iPhone 4.