Editors' note: This slideshow has been updated with four new slides. The original publish date was April 9, 2010.
Multitasking is the biggest win from iOS 4. It's great to have this common smartphone feature, though we're disappointed it will come only to the iPhone 3GS (or later) and not the iPhone 3G.
To access the multitasking menu, double tap the Home button. You'll see a list of currently running applications that you can scroll through using a sideways finger swipe. You then open an application by tapping its icon.
Double-tap the home button to bring up the multitasking screen and scroll one screen to the left to access iPod controls. You also can lock the screen rotation from this screen or return to iTunes with a touch of your finger.
We also welcome the new ability to add home screen folders. To create a folder, just drag icons on top of each other. The folder will then appear as a square with tiny icons of the included app inside. Tap the the folder to open it.
Find all the images that have a specific friend in them using the Faces sorting feature. You'll need to have already used the face recognition options in iPhoto or Aperture and synced with iTunes to use this feature.