Turning off the start-up sound (Ta-Da)

[progginRay]

Just stumbled over Psst, an app that seems to do what you need.
I haven't tried it out myself, though.

http://www.mistatree.org/Freeware/Psst/

Hope this helps

[DeltaMac]

Originally Posted by progginRay

Just stumbled over Psst, an app that seems to do what you need.
I haven't tried it out myself, though.

This app has already been discussed in this thread. It does not work on this MacBookPro

[the yapster]

Try this app, I use it without incident. For whats its worth I think it is the height of arrogance that Apple would program this chime to operate at full volume, with or without headphones connected and not allow facility for a user to at least turn down the volume. Who wants to disturb every passenger on a long haul flight simply by turning on their mac?

http://www5e.biglobe.ne.jp/~arcana/index.en.html

[Brinkster]

I don't know if you have found a solution to the startup sound "problem" but I've tested one that works on my MacBook Pro (Core2Duo).
It's a System Preferences add-on I downloaded from macupdate.

Hope this helps you.