The Orange Screamer - A wide-area annoyance device

This is a pocket sized turbo whistle or siren which emits a loud and extremely annoying WHEEEEEEEEEEE when you blow into it. I've done a full write-up on Instructables : http://www.instructables.com/id/The-Orange-Screamer/ and you can see a video of it in action here : https://vimeo.com/105474925. (The camera mic doesn't really pick up the full range and volume of it.)
This design was inspired by Instructables user Kiteman, who published a perspex laser cut version.