FILTER: nsf CSS-based replacement for flickering backgrounds

s@</head>@<style type="text/css">\n\
 /* Style sheet inserted by Privoxy's nsf filter. */\n\
 body{background:\#406480;}\n\
 </style>\n$0@

s|body background="/images/bg.gif"|body|g

http://geneticrubbish.wordpress.com/2009/01/31/the-nsf-website-background/

Fix the background at the NSF

Privoxy nsf filter:  Change nsf.gov background

filter

Perl