Note: this post is from 2007, outbound links may be broken.
FindSounds: Find sounds on the internet with ease
With FindSounds you can easily do a search for particular sounds on the internet.
FindSounds.com is a free site for finding sound effects and musical instrument samples on the Web. It is a Web search engine, like Google and AltaVista, but with a focus on sounds. It provides powerful features, yet is simple and easy to use, and suitable for all ages. Note to parents: audio files containing obscenities are filtered out so this site is safe for children.
Screenshot of FindSounds search result for Pinball
You can search for AIFF, AU and WAVE files of specific quality and size in many different categories. Give it a try!