FactCheck.org bills itself as a non-partisan, nonprofit website and as a "'consumer advocate' for voters that aims to reduce the level of deception and confusion in U.S. politics."  A project of the Annenberg Public Policy Center at the University of Pennysylvania, it is primarily funded by the Annenberg Foundation.

An offshoot project is FactCheckEd.org which serves a different purpose: providing resources to help HS students learn to think critically and analytically.  The site features over 30 lessonn plans that can be used individually or in a series.

Of particular interest might be the plan: Wikiality which illustrates the potential pitfalls of using Wikipedia as a reference. 

Drawing on two controversies – Stephen Colbert’s on-air altering of his own entry and his call for viewers to alter a second entry, and the false biography of Nashville's John Seigenthaler – students will discuss the ease with which false or misleading information can be added to Wikipedia, and they’ll search Wikipedia entries for inaccuracies.

Check it out: FactCheckEd.org