When we covered one of the future Windows Phone 7 Mango features, respectively the ability to disable camera shutter sounds, we turned to Android, iOS and BBOS as examples of platforms that do not allow for silent camera operation as a privacy protection feature rather than a lack of the OS itself. But there will always be hack and the latest allows you to control the volume of the Samsung Galaxy S II camera sounds.
Without going into a privacy debate of snapping pictures unnoticed, you can now have your Samsung Galaxy S II camera sounds obey System Sounds volume, meaning you can turn the volume up, down or off. There are two methods to achieve this (one implies creating a file and the other grabbing the file and placing it on your smartphone) and both are described in the tutorial over at the source link. Just remember that there are countries and regions — like Japan and South Korea — where cameraphones are required by law to generate a sound upon snapping a picture — and there’s also a US Bill proposal called Camera Phone Predator Alert Act.
Source: XDA Developers