I attended an interesting workshop this morning that involved a technical discussion of the types of background checks that are available for employers. While most of the discussion was on criminal background checks, evidently a recent study shows that 67% of all resumes contain errors, misstatements or outright fraud.
Most companies who perform background checks for employers are updated regularly on "diploma mills" so that certifications or degrees that are false can be caught.
In a competitive work environment, candidates may be tempted to embellish their work history or education. Please don't do it -- your personal integrity is at stake, and no employer will hire you (or keep you) if they find false information in your application.
On a related note, here's a helpful article from the New York Times on ten things job applicants should do.