The JScreenFix Java applet helps fix stuck pixels and image persistence on LCD screens and reduces burn-in on plasma screens. The applet runs safely inside a web browser, does not require installation and works with Windows, Linux and Mac computers.
JScreenFix repairs most stuck pixels in under 20 minutes, and mild screen burn-in within 12 hours.
http://www.jscreenfix.com/index.php
I just stumbled upon this site - use at your own risk