You can always block the speaker with your finger, or flash a different firmware.
Thanks for your reply. But do I need to unlock/jailbreak the phone in order to flash another firmware?
Go to settings -> ringtone+sound (or something like that, the first one) and then you can disable the shutter sound down this setting panel.
The India CV firmware that I run doesn't have the option to disable shutter sound. It's just not there in the settings.