If you are a regular user of the iPhone's camera 4/4s interest you find accessories that help reduce reflections that appear in photographs you take. One accessory that can help us avoid reflections oblique Circular polarizer is a filter that fits the camera of your iPhone.
To implement one of these filters on the iPhone, we need a case to which the polarizing filter may be fitted easily. By placing the lens in the iPhone's camera, automatically avoid glare, ideal for taking pictures through non-metallic surfaces, such as through a window or a car. That if the camera flash will be blocked. This will be the result before applying the lens, then:
You can find one of these web filters USB Fever for about 29 euros.
Link: USB Fever .