That's important, because if you're a heavy user during a business trip, a dead battery is simply unacceptable.
In fact, it's 24 percent thinner than the already thin iPhone 3G S. That matters, because if you carry a bulky phone in your breast pocket, it looks like you're packing heat. In a pants pocket, a bulky cell phone makes it look like you're smuggling a grilled cheese sandwich -- not the most professional look.
The iPhone's sleek, thin size means you can slip it into a business suit pocket and still look professional.
However, for business people, the iPhone platform's 225,000 apps are likely to provide every business user with not only general-purpose business apps, but narrowly focused options for whatever your particular profession is: Sales, real estate, finance, retail -- whatever it is, you'll probably have your pick of many different apps designed specifically for what you do.
Apple's latest creation probably isn't the best phone for everyone. But for most professionals, there is simply nothing better for business than the iPhone 4.