If you're wondering how the focus feature allows you to utilize the new iPhone 3GS camera, here's a quick demonstration I made in my kitchen. You simply click the object you want to focus on (on your touchscreen) and it goes into focus. Also note the new camera takes 2048x1536 (3 Megapixel) pictures instead of the 1600x1200 (<2 Megapixel) photos of the older model. Picture comparison between 2G (Edge) iPhone / Old iPhone Camera and new 3GS Camera: Older iPhone "focused" (aimed at) red cactus: New iPhone focused on red cactus: Old iPhone focused on green cactus: New iPhone focused on green cactus: Old iPhone, no specific object of focus in kitchen, wider shot: New iPhone (I think it focused on the left pot, but I did that accidentally):
