The camera on Samsung Galaxy S2 is amazing, its 8.1MP camera takes HD pictures and videos. I found myself taking more and more pictures with it. However, Due to the privacy concerns, the camera shutter sound can’t be muted and it is really loud. It was bearable with single shot but made my time-lapse video shooting experience bad.
So I decided to mute the shutter sound by myself. After looked around, I was able to mute it completely and here is how I did it.
1. It requires the superuser permission, another word, you will need to root your Samsung Galaxy SII.
2. Use a file manager that can access system folders, I use the Root Explorer.
3. In the Root Explorer, goto the folder /system/media/audio/ui/
4. Within the /system/media/audio/ui/ folder, mount the folder as R/W so we could rename the sound files.

5. Once the system files are editable, look for the file named Shutter_01.ogg and rename it to something else. Just don’t delete it in case you may want to restore the camera shutter sound later.
6. Put the system folder back to R/O then exit Root Explorer.
7. You’re done! Go to camera and enjoy!

You the best.
iv downloaded the free edition of root explorer and dont seem to have the mount r/w options, or i simply dont know how to switch th folder from r/o to r/w, help please =)
try ES file explorer. It should work however I didn’t try it.
https://market.android.com/details?id=com.estrongs.android.pop&feature=related_apps
How can I silent the shutter sound with out paying for the root explore ?