Disabling the Macbook Startup Sound

When you start a macbook you hear a kind of control sound (beep) which means the hardware check was ok. This sound is pretty annoying even more when you start your laptop in a public room and suddenly everybody is looking at you.

After some research I found out that Psst (a Mac application) allows you to disable this startup sound. So happy booting, without disturbing everybody around you.

Marc