As of iOS 4.3, four and five finger gestures are being added to the software. Using them, you can easily slide back and forth between running apps, pull up the quick-switch menu, and jump back to the home screen.
Oddly they are currently locked for developer use only, but that hasn’t stopped non-developers from enabling them.
Our friends over at GottaBeMobile.com have a guide that shows you how to unlock the gestures on any (original, or the new one) running iOS 4.3. Unfortunately you’ll need a Mac, and it’ll run you $5.99, but it almost looks worth it; check out the video of the gorgeously animated gestures in action:
The gestures are certainly more quick and natural than having to double tap the home button, then tap and on-screen element to switch apps. And while they may be natural in terms of execution, they lack initial intuitiveness. Until they are taught the first time, it isn’t straight forward to try four or five finger gestures.
There’s also the question of whether or not implementing these gestures will limit developers. In multiplayer games like Harbor Master, you can have multiple people docking ships at once. In MultiPong, four player mode requires that each player have a finger on the screen at once. It’s possible that iOS might interpret the movement of four individuals’ fingers as a single four-finger gesture, and that would really wreak havoc on the game experience if you’re defending your goal with a paddle then suddenly switching to another app!
If I had to guess, I’d say that this is why Apple hasn’t yet enabled the gesture for all. They probably need to give developers time to specifically disable such gestures in apps that would be ruined in some way if an improper four or five-finger gesture was detected.