Re-live your days of extension conflicts and cooperative multitasking with this pack of alert sounds ripped straight from OS 9 and converted to a modern format.
Installation
Mac OS X 10.0-10.3: Copy the AIFF files to (Your Home Folder)/Library/Sounds/
Mac OS X 10.4: Copy the AIFF files to (Your Home Folder)/Library/Audio/Sounds/Alerts/
I don’t have 10.5 or 10.6, but the Internet says Apple moved it back to (Your Home Folder)/Library/Sounds/