There's a big difference between the Galaxy S and iPhone 4. No, not iOS vs. Android 2.1 or even Retina vs. Super AMOLED. We're talking batteries: one is removable and one isn't -- guess which is which? This perennial iPhone "feature" has spawned as entire industry of device-specific accessories that sate the need for more juice while simultaneously killing the form (and aesthetic) of an otherwise pocketable gadget. But hey, it's your only choice when you're either too busy (