8OO8  It looks like the only change between the previous version and this version, v2.4, of Startup Crime Stopper is the addition of an Italian localization (thereby giving the developer more publicity, once again, for his grossly overpriced app).

What's next for version 2.5, Latvian localization? I can hardly wait.

By the way, the previous commenter's suggestion that you can go for Tinkertool System instead of this app is right on.

TinkerTool System is around $10 and is one of the excellent full featured maintenance apps with a plethora of great, useful features, including one to mute your Mac's startup chime.

Now, if AlphaOmegaSoftware could come up with something really innovative and brilliant like TinkerTool System(but I won't hold my breath, sigh...), I just might change my otherwise low and contemptuous opinion of that software company.  
(Version 2.4)

HURZ  ROTFLOL.....

>>> TinkerTool System, and you get much more in a safer way  
(Version 2.3)

8OO8  There's absolutely no reason to spend the absurd price of $19 or $20 that AlphaOmega asks for this, nor, actually, is there any reason to spend ANY money for a chime stopper when there are a number of totally fine FREE ones out there.

I've been using "Psst!" for some time now. It's free, of course, it been working flawlessly for me, and you can even adjust the chime volume from off, to whisper quiet, all the way up to full volume via a slider.

It's your mazuma, though. Ya wanna pay good money for one? Then the pleasure is all yours.  
(Version 2.2)

SEQUOIA1  The point of apps that turn off the startup sound: some of us have extremely loud stereo systems attached to our Macs. Some of us also shut our Macs down every evening, and have it start up automatically at 4am, to run backups, diagnostics, etc. Some of us have home offices, which would mean these daily startups would wake the cat, the people sleeping, and rattle the windows. So, for those of use with the above situations, a simple, free utility that silences the startup sound is exactly what we need.

True, we could remember to turn down our speaker set every evening before retiring. But who's really going to remember that, and why? And if you're relying on the startup bong to determine the health of your Mac, the least of your problems is going to be a sound or two.

There is no need to pay $15 for this app. On all my Macs, which are all running 10.4.3, I use the free StartupSound.prefPane which is tiny, stable and free. You can find it here:

http://www5e.biglobe.ne.jp/~arcana/StartupSound/index.en.html  
(Version 1.10)

AOS=POS  StartupSound.prefPane is an unobstrusive pref pane that allows for muting the start up chime completely or setting its volumel to the level you choose. More good news: it's free.  
(Version 1.5)

JIMW  Tip: At least on a G4 Sawtooth machine under 10.3.5, if you mute the sound with the mute button on the keyboard before rebooting or shutting down the sound will not play when starting up and you will have saved yourself $10. Another obvious trick is to plug an earphone or headset into the headphone jack.

As I have mentioned in other comments regarding other products from this company, I tend to be skeptical of anything this company produces and steer clear of all of their products as I have found that in most cases the majority are overpriced, have little real value, may be buggy, or are shareware equivalents of freeware available elsewhere.   
(Version 1.5)

ANONYMOUS  *sigh* I'm going to buy 10 songs from the ITMS... and try StartupSound.  
(Version 1.5)

ANONYMOUS  I agree that paying for this is just crazy, but PascalChiotasso's comment.... He can't even spell rubbish....  
(Version 1.5)

MRDREAM  Ten dollars for this? Hell no!  
(Version 1.2)

ANONYMOUS  Asking money for such a simple thing is simply shameful, especially when there are free and always better alternatives. One of these is StartupSound (a Preference Pane which will allow you to adjust the volume of the starting sound) that is to be found at:

http://www5e.biglobe.ne.jp/~arcana/StartupSound/download/StartupSoundPrefPane100.dmg.gz

The Read Me is in Japanese but I hope everybody around here is able to install a Pref Pane. Rotten banana! It could give another idea the developer: Install Preference Pane, by AlphaOmega Software.  
(Version 1.2)