Auto Mute is a small utility to make a Mac silent when it’s turning on or is waking up. The solution is as easy as a pie! The sound is automatically muted when the computer is turning off or is going to sleep/suspend mode. Also there is an option to mute sound when screensaver appears. So the next system start is absolutely silent even if you forgot to turn the sound off in previous session. After restart you can unmute sound effects manually, using a shortcut combination. Moreover, you may use this keyboard shortcut to quickly switch the sound on and off when working.

Requirements:
OS X 10.5- 10.6
Universal Binary