*This tweak is for Jailbroken devices only*
Apple has actually introduced “multitasking gestures”, a new set of multitouch features for iOS 4.3 that allows users to switch between apps, go back to home screen and bring up the multitasking tray by using 4-5 fingers.
These gestures were not released to the public. They are only made available for developers. This means you can activate it using Xcode, a developers’ program on Mac ($4.99 on Mac App Store).
HOWEVER, if your device is jailbroken, you can try this new Cydia tweak called MT Gestures. It allows iPhone 4 and iPod touch 4g owners to turn on the multitasking gestures — with the same preference panel seen on the iPad. It’s available in ModMyi’s repository.
Don’t know how to use multitasking gestures? Check out this demo video below.