Here’s something from a while back (I’m tidying out my rss reader). The current president has shown great innovation in the field of signing statements, essentially amendments to laws that he signs explaining what he understands by them. I’m not sure what purpose they could constitutionally serve – the law is the law, interpretation is for the courts, the executive should just implement – though arguably they could set an early standard for what exactly what ‘implementation’ means in each case. That’s not quite how President Bush has chosen to use them, however.
Our example comes from The Department of Homeland Security Appropriations Act of 2007, section 503(c)(2), describing the qualifications required of a FEMA Administrator (i.e. the head of FEMA):

In response we have the President’s signing statement:
Section 503(c)(2) vests in the President authority to appoint the Administrator, by and with the advice and consent of the Senate, but purports to limit the qualifications of the pool of persons from whom the President may select the appointee in a manner that rules out a large portion of those persons best qualified by experience and knowledge to fill the office.
If I was looking for a FEMA boss I’d consider the conditions in the Act to be an absolute minimum. I’m at a total loss to think what qualifications someone might have that would suit them for the role, but wouldn’t meet those conditions. Anyone from the emergency services, Coast Guard, border patrol, National Guard, or government departments dealing with public safety would easily qualify on the first count. And the second is an entirely reasonable requirement for someone leading an organization as important as FEMA.