Here's how to silence it on the stock Sprint version:
Difficulty level: 2/10
1. Root your phone
2. Using your favorite Root Explorer open /system/media/audio/ui and rename camera_click.ogg to camera_click.old (ironically, on the LG phone this is not the audio file used by the stock camera, but if you don't delete this file other cameras like CameraZoom will have a shutter sound)
3. In /system open build.prop. Make a backup before editing. About 2/3 of the way down under the group heading "ADDITIONAL_BUILD_PROPERTIES" is one line that reads "ro.camera.sound.forced=1" Change the "1" to "0". Save the file. Reboot your phone
After doing this, when the phone is on silent there is no shutter sound. If you want a silent shutter when the ringer is on, go to System-Sound-Volumes and make the "Touch feedback & System" volume zero.
Whoala...silent camera.