With the release of iOS 5, iPhone and iPad photographers now have a few new settings and features. The Camera and Photos apps have both been updated in iOS 5, but how those updates appear depends on the device you're using.
On the HDR-equipped iPhone 4 (and likely on the 4S as well), the Camera app now displays an Options button at the top of the screen between the flash and camera selection buttons. A tap on the button displays two switches -- Grid and HDR -- that are used to turn on or off a rule of thirds grid and the High Dynamic Range Imaging (HDR) capabilities of the camera. On the iPad 2 and iPhone 3GS, neither of which have HDR capabilities, the grid switch is still available to assist in taking more aesthetically pleasing photos.