I didn't go exactly in the direction you guys we're asking for.. but I did freak some people out, and had a lot of fun doing it. That's gotta count for something.
Good luck everybody!
[video=youtube;EJi61JPsbsQ]http://www.youtube.com/watch?v=EJi61JPsbsQ[/video]
Credits to David Berglas and Wayne Houchin for the first two effects, the last is... original? I doubt it, but I came up with it independently.