Web Site Optimization recently published a study, "eGovernment Site Credibility: Comparing Speed, Accessibility, Typos, and Validity" in Optimization week in which they asked "Is your government credible, or not to be believed? See how five major powers stack up in this web site shoot out." TextTrust.com was used to spell check the sites and is prominently featured in the study.
http://www.optimizationweek.com/reviews/egovernment/