I have a 3Gs and have upgraded to iOS 4. Is there any way to turn multitasking off? I don't really use it, and when I access the open apps (by double clicking the home button), I usually find many apps left open in the multitasking bar (which I then have to close). I've also noticed a decrease in my battery life, so I think it might be because of the multitasking and leaving all those apps "open". Thanks in advance.