Here are two sounds that I created with SoundEdit 16 so that I wouldn't have to endure the boring sounds that ship with all Macintosh's. They both have an electronic sound similar to something you might here on Star Trek (SNG, DS9, Voyager, etc.)
They are both in the System 7 sound format at 8bits 22Khz so all you have to do is drag them to your system file. Feel free to give these sounds to your friends or whatever, but if you like them please send me some e-mail. Enjoy!