CStrauss has kindly given me permission to use his image in this tutorial.
A 2 colour vignette with masking.

The video is here:
http://prixat.zxq.net/tutorials/vignette.swf
(11MB, SWF format, 800x600, no sound)

I would recommend downloading it and playing it from your hard drive.

Try a free SWF player like this one:
http://www.globfx.com/products/swfplayer/ to get better pause/rewind controls.

regards
prixat