Make your Mac sound retro

Here's someone who has them already in AIFF format, for everyone's convenience:

http://sagefire.org/2005/04/04/macos-classic-sound-pack-v14/

The system sounds available for download are in .wav format and will not work with OS X. What you need to do is this: First, download the archive of system sounds and unzip it. Then load iTunes, go to Preferences, then Advanced and then Importing. Change the "Import Using" setting to "AIFF Encoder" and then click "OK". Then hold down the option key and select the "Advanced" menu. Select the option that says "Convert to AIFF..." and when the dialog pops up, select all the files that were in the archive and iTunes will import them and convert them to AIFF format. You can them copy them from wherever iTunes puts them (probably in a folder named Unknown Artist) to ~/Libarry/Sounds. (You can also delete them from iTunes if you wish.) Open System Preferences, select "Sound" and you'll find the sounds available to you. It's a bit of a chore but you need only do it the once and you too can enjoy retro sound goodness. Hope that helps.