The "fluttering" is real ... Turn the bar 180 degree than you'd normaly use it , pick a note (or make it sound by a legato) then hit it hard and quick... Check Dream Theater "Under a glass moon" solo , near the end of it.

At the same position (180 degree) , hold the bar and shake it rapidly while playing legato stuff ... This gives and indian sitar-like sound... Check Steve Vai for that one.

Dive the bar , and tap a harmonic by your fretting hand's middle finger , then pull the bar , shake it or whatever ... It will always sound cool , check Pantera's Dimebag for this one.

A variation of the above one is to use it with Pinch harmonics instead of tapping or natural harmonics , like Satch.

I remember I've read an article on wierd noises by Steve Vai , I think there's a copy of it on his site ... Check it out , it's usefull.