IBNeko's Journal-Nyo~!

Source: http://www.howardforums.com/archive/topic/1069013-1.html
Corrections source here: http://www.gsmhosting.com/vbb/archive/index.php/t-311875.html

Essentially:
1) Get into the "Test mode" menu: *#8999*8378# (the source had it wrong. See bottom second source)
2) [2] for H/W Test
3) [2] for Audio Settings
4) [1] for Rx Path (recieve path - I guess, anything to the User.)
5) [9] for Melody gain
6) [1] for Normal
7) Use [c] and the number to set "Vol. 1" to 0 (default:10). [OK] or [...Save] to continue.
8) Same thing; Set "Vol. 2" to 0 (default:14)
9) Same thing; Set "Vol. 3" to 0 (default:19)
10) Same thing; Set "Vol. 4" to 0 (default:24) - This is the important one. The camera shutter is set on this volume.
11) If desired, you can set "Vol. 5" to 0 as well. ::shrugs:: (default:30)

My settings will be (0, 10, 20, 0, 31). 31 is the max: volume is modded (%) by 32, so 32=0.

Next modification:
Turning off the goddamned startup/turn on sound...

---
For the record, here's the menu breakdown and default (I think. Some may be different since I've already played with the normal user accessable settings) values for the t319, t-mobile to go phone: ("|" = new line)
( Default values )

[edit]
Apparently the shutter-sound requirement is due to privacy law: "Anyway, this is an easy way to stick it to the lame-o nanny state European/Asian countries that ruined it for us all with their over-reaching "privacy" laws that mandated the shutter click." - source 1.

Power on/off sound options are there in the normal user menu. Doh. ^^;;

[edit2]
codes: (source: http://www.3g.co.uk/3GForum/archive/index.php/t-25686.html, it's for another phone, but it works for this one too.)
*#7465625# = Check Locks (7465625=pinlock. Prepend with * to enable, # to disable. Code.. apparently has to be read off using a computer. :P Spiffy though.)
*7465625*638*Code# = Enables Network Lock (638=net)
#7465625*638*Code# = Disables Network Lock
*7465625*782*Code# = Enables Subset Lock (782=sub)
#7465625*782*Code# = Disables Subset Lock
( More codes.. )