Just a simple particle emitter mesh spinning around on a CurveCircle path.
I had to use a small Python script to rotate the CurveCircle to get the “funky” effect near the end since adding a Rot KeyFrame didn’t seem to do anything.
The animation is about 11 MB.
Sorry, it didn’t seem to compress down too well.
that looks cool.
can I get that python script? 
Sure, here’s the whole blend file:
http://users.xplornet.com/~gimble/sine_python_23.blend
Pretty rough implementation script-linked to the CurveCircle.
If you quit the animation at any arbitrary frame, you’ll need to reset the CurveCircle 's initial rotation after returning to Frame 1.
Very nice!!! I also downloaded ur blend file…thanks for sharing