iPhone multitasking gestures On iPad, there are some useful multitasking gestures such as swipe between applications.

How do I enable multitasking gestures (a la iPad) on iPhone 4?
iOS 4.3 beta had this feature.
I used it and it wasn't that nice.  The all of your fingers toward the middle brings you home gesture was difficult to use at best.

As of right now, you have to jailbreak your device and install the Zephyr app from the BigBoss default repo.

It lets you configure how it works, which is a nice bonus.