Sound Dogs
"Downloadable Sound Effects Since 1997" Listen to free sound effects and production music previews by clicking the Mp3 buttons. Create an account to download Hollywood sound effects and production music tracks.

From the Department of Cheap Research: Easy Money
When I was a kid I noticed, with inexpressible disgust, that in sci-fi movies the whole universe spoke flawless midwestern American English. So to create an extraterrestrial accent for movies (and make a million dollars) I worked out a system. You take your English text, and you transcribe it phonetically backwards. You rehearse that until you can rattle it off, and then you record it.

Top 5 Sites for Free Sound Effects Downloads
Before you open up your wallet for expensive software or try to make your own sound effects, you may easily be able to find free sound effects on the Web. There are plenty of great resources available online. Best of all, it doesn’t have to cost you anything!