So, I see many posts and threads on here about the mysteries of multitasking and its effect on battery life. Well, as I was purchasing my iPhone earlier (at launch at the Apple Store), the employee who helped me had said that some customers were coming back into the store a few hours later with significantly drained battery, and went through the process of showing me how to close the apps with the little red minus. So, according to that guy, multitasking can get out of hand and kill your battery... so maybe we DO need to be careful?...