Flip Out
The Center for American Progress has published fact sheet full of flip-flops... attributed to W, and not John Kerry. The big ones, in my eyes (and excluding the whole WMD subject):

BUSH OPPOSES THE DEPARTMENT OF HOMELAND SECURITY..."So, creating a Cabinet office doesn't solve the problem. You still will have agencies within the federal government that have to be coordinated. So the answer is that creating a Cabinet post doesn't solve anything." [White House spokesman Ari Fleischer, 3/19/02]
...BUSH SUPPORTS THE DEPARTMENT  OF HOMELAND SECURITY "So tonight, I ask the Congress to join me in creating a single, permanent department with an overriding and urgent mission: securing the homeland of America and protecting the American people." [President Bush, Address to the Nation, 6/6/02]

BUSH SUPPORTS MANDATORY CAPS ON CARBON DIOXIDE... "[If elected], Governor Bush will work to…establish mandatory reduction targets for emissions of four main pollutants: sulfur dioxide, nitrogen oxide, mercury and carbon dioxide." [Bush Environmental Plan, 9/29/00]
...BUSH OPPOSES MANDATORY CAPS ON CARBON DIOXIDE "I do not believe, however, that the government should impose on power plants mandatory emissions reductions for carbon dioxide, which is not a 'pollutant' under the Clean Air Act." [President Bush, Letter to Sen. Chuck Hagel (R-NE), 3/13/03]

BUSH SAYS GAY MARRIAGE IS A STATE ISSUE... "The state can do what they want to do. Don't try to trap me in this state's issue like you're trying to get me into." [Gov. George W. Bush on Gay Marriage, Larry King Live, 2/15/00]
...BUSH SUPPORTS CONSTITUTIONAL AMENDMENT BANNING GAY MARRIAGE "Today I call upon the Congress to promptly pass, and to send to the states for ratification, an amendment to our Constitution defining and protecting marriage as a union of man and woman as husband and wife." [President Bush, 2/24/04]