Available only on Japanese iPhones
You might think iPhone 3Gs are equal all over the world. Well, not quite.
There are something that is only available on Japanese iPhones: the shutter sound in silent mode.
In Japan, the camera on mobile phones can be as high as 5.2M Pixels and they could be used for sneak shots such as spy shots and/or dirty pictures.
For this reason, Japanese manufacturer have stopped the disabling of shutter sound in silent mode; some manufacturers have even put louder shutter sound.
Many cell phone collectors have wondered if the sound will be on on the iPhone 3G especially because they knew the original iPhone 2G killed the shutter sound in silent mode; well, the answer was 'YES' and, although quietly, the Japanese iPhone 3G would make a sound if you take picture even when it is set to silent mode.