Power on screen

Does anyone know how to change that black screen into something else when i power on my powerbook? I use it a lot in class so i have the speakers on mute not to disturb anyone so i dont know if i turned my powerbook on or not. I've done searches but couldn't find anything. Could anyone help me out on this? Or is there no such solution. thanks!

I dont think thats possible, but theres an app called psst! thatll allow you to mute or adjust the volume of the startup chime, just adjust it to so low that you can hear it, but it wont be disturbing to others.

Sleep instead of shutting down?