Some iPhone applications have preferences to set an accelerometer lock, which keeps the orientation of the app in one direction no matter which way the iPhone turns. Unfortunately, most commonly used apps do not have this feature.
Rotation can be switched off when viewing photos on the iPhone Camera Roll or Photo Library. When viewing a photo, hold down with one finger on the photo as if you're trying to copy the image.
The Copy indicator box will appear over the photo. Now rotate the iPhone in any direction and the photo will retain its current orientation. A few seconds after letting go of the screen the Copy indicator box will disappear.
Accelerometer rotation will be restored as soon as you touch the image again or swipe to the next photo in the set.Sometimes taking a photo at a strange angle or facing downward will produce awkward results. The orientation of the iPhone confuses the camera app and your photo is perpetually spun the wrong way. With this tip you can temporarily fix the problem.
Now if only there was an easy way to alter the recorded orientation of a photo right in the camera app...