You're so right, rooster!
Presidential usage (of signing statements):
The first president to issue a signing statement was James Monroe. Until the 1980s, with some exceptions, signing statements were generally triumphal, rhetorical, or political proclamations and went mostly unannounced.
Until Ronald Reagan became President, only 75 statements had been issued. Reagan and his successors George H. W. Bush and Bill Clinton have produced 247 signing statements among the three of them. By the end of 2004, George W. Bush had issued over 108 signing statements containing more than 505 constitutional challenges.  As of October 4, 2006, he had signed 134 signing statements challenging 810 federal laws. 
The upswing in the use of signing statements during the Reagan administration coincides with the writing by Samuel A. Alito – then a staff attorney in the Justice Department's Office of Legal Counsel – of a 1986 memorandum making the case for "interpretive signing statements" as a tool to "increase the power of the Executive to shape the law." Alito proposed adding signing statements to a "reasonable number of bills" as a pilot project, but warned that "Congress is likely to resent the fact that the President will get in the last word on questions of interpretation."
Did Congress resist? Not much! (my words)
A November 3, 1993 memo from the Clinton Justice Department explained the use of signing statements to object to potentially unconstitutional legislation:
If the President may properly decline to enforce a law, at least when it unconstitutionally encroaches on his powers, then it arguably follows that he may properly announce to Congress and to the public that he will not enforce a provision of an enactment he is signing. If so, then a signing statement that challenges what the President determines to be an unconstitutional encroachment on his power, or that announces the President's unwillingness to enforce (or willingness to litigate) such a provision, can be a valid and reasonable exercise of Presidential authority.
This same Department of Justice memorandum observed that use of Presidential signing statements to create legislative history for the use of the courts was uncommon before the Reagan and Bush Presidencies. In 1986, Attorney General Edwin Meese III entered into an arrangement with the West Publishing Company to have Presidential signing statements published for the first time in the U.S. Code Congressional and Administrative News, the standard collection of legislative history.
Signing statements may be viewed as a type of executive order without congressional oversight. Other types of executive order are national security directives, homeland security presidential directives, and presidential decision directives, all of which deal with national security and defense matters.
 Controversy over George W. Bush's use of signing statements
There is an ongoing controversy concerning the extensive use of signing statements to modify the meaning of laws by President George W. Bush. In July 2006, a task force of the American Bar Association described the use of signing statements to modify the meaning of duly enacted laws as "contrary to the rule of law and our constitutional system of separation of powers".
George W. Bush's use of signing statements is controversial, both for the number of times employed (estimated at over 750 opinions) and for the apparent attempt to nullify legal restrictions on his actions through claims made in the statements. Some opponents have said that he in effect uses signing statements as a line-item veto although the Supreme Court has already held one line item veto bill to be an unconstitutional delegation of power in Clinton v. City of New York.
Previous administrations had made use of signing statements to dispute the validity of a new law or its individual components. George H. W. Bush challenged 232 statutes through signing statements during four years in office and Clinton challenged 140 over eight years. George W. Bush's 130 signing statements contain at least 750 challenges.  In the words of a New York Times commentary:
"And none have used it so clearly to make the president the interpreter of a law's intent, instead of Congress, and the arbiter of constitutionality, instead of the courts."
The signing statement associated with the McCain Detainee Amendment, prohibiting cruel, inhuman and degrading treatment of detainees in U.S. custody attracted controversy:
"The executive branch shall construe... the Act, relating to detainees, in a manner consistent with the constitutional authority of the President to supervise the unitary executive branch and as Commander in Chief and consistent with the constitutional limitations on the judicial power...."
This statement specifically invokes the unitary executive theory, which according to its adherents argues that the President, in his capacity of Commander-in-Chief, cannot be bound by any law or by Congress since anything hindering him in that capacity can be considered unconstitutional. With his signing statment to the McCain Detainee Amendment, the President has reserved his authority to challenge parts of the law passed by Congress.
In other words, Bush prefers his role as Commander in Chief and sees it as being much more important than his role as President. Like a little Il Duce strutting around....
THAT's one of the reasons I don't think Bush will leave the presidency in 2009 without some kind of attempt to try to declare martial law, which might allow him and Cheney to stay in power.