A Great Government Web Site Dedicated to Plain Language: http://www.plainlanguage.gov

© 2010 Ugur Akinci
President Barack Obama ushered in a new age in technical communications by signing the “Plain Writing Act of 2010” on October 13, 2010.
According to this, within one year, all U.S. government agencies are supposed to generate only documents written in a plain language.
I found this excellent federal web site dedicated to the Plain Writing movement: http://www.plainlanguage.gov
The site is maintained by The Plain Language Action and Information Network (PLAIN), a group of federal employees from many different agencies and specialties.
The site defines Plain English as “robust and direct—the opposite of gaudy, pretentious language. You achieve plain English when you use the simplest, most straightforward way of expressing an idea.”  To that I’m sure every technical communicator is saying “Amen!”
I especially recommend their EXAMPLES page where you can find a number of Before-After examples to study and learn from.
Also Recommended: Center for Plain Language