Find that shutter jingle irritating? Here's how you can remove it,

Open the registry editor > navigate to the following key
HKCU\Software\Samsung\Camera
Modify the ShutterSound to a number greater than 2 shall do the work. However, if you modify the sound settings in the camera, you will have to modify the registry again.

Another persistant solution, you got to find a wave file that playback nothing! (There's a silence.wav located in the windows directory) Decide on which shutter jingle you are going to replace. Rename your silent wave file to Shutter0X.wav where X is the number corresponding to the shutter jingle in the camera settings.  Copy this file into the windows directory and voila! Your camera remains quiet when taking photos

This is one of the most mysterious task to be done on the phone. The manual does not document it, and only a handful of the users reported success.

After torturing my omnia, finally I can confirm the following is the valid methods to do a hard reset using the hardware keys.

When Omnia powered off,
hold onto the Call and Cancel buttons, press and hold the power button for a approximately 5 seconds until the reset screen shows up. If you do it wrongly, you will hear the samsung jingle and the startup animation.

When it is on,
hold onto the Call and Cancel buttons, poke the soft reset hole and the reset screen shall show up.

This is a snapshot of the reset screen.

By the way, this hard reset does not erase the 16GB memory. To reset everything, you could use the software hard reset by going to Settings > Hard Reset. There is also option to format the storage card.

One point to note though, if you decided not to format and press cancel, that will soft reset the phone.

P.S. Hard Reset means restoring it to the factory state, so all your files and programs will be removed! Backup your files before proceeding with the reset!