Adding Additional Sound Effects to iMovie 3?

[David]

Downloadable Sound Effects?

Apple offers a group of sound effects on their webpage:
http://www.apple.com/imovie/audio_effects.html

If you click on them, you can hear them one at a time. Or you can 
download them, which I've done. But I can't figure out how to import 
them into iMovie 3. There's no info in the "Help" and dragging and 
dropping doesn't work. I couldn't find where the stock sounds are 
stored. Any help here? I could drag them into iTunes but then they 
wouldn't be available to the other users on my computer.

DC