This plug-in can easily convert every colored image (in an html page) into a B&W greyscale image. Read the plugin API on here http://www.gianlucaguarini.com/canvas-experiments/jQuery.BlackAndWhite/demo.html.
Plugin Showcase
If your want add a new entry please fork this README file
IMPORTANT
the script works only for the images hosted on the same server in which the page is loaded!
THANKS
Thanks to Jeffrey Way for the inspiration ( http://jeffrey-way.com/ )