'Is Bush Wired?' - Anno 2005

This is not definitive proof that Bush uses an earpiece at all public occasions. But if you analyse the combination of his words, his interrupted speech and his body movements, you cannot help but come to the conclusion that someone is feeding him the words he has to say.
And check out his smirk at the end! As if he's saying 'I know something you don't...'

see it here.