What is the Biblical basis for disbelief in the doctrine of the Trinity?

In related form to a previous question on the basis *for* the Trinity, what is the Biblical basis for disbelief of the doctrine? Not all Christians (and perhaps not all branches of Christendom) hold to a Trinitarian view - how are those views justified from the Bible? Specifically, what verses do non-Trinitarians cite to support their views / contradict the doctrine of the Trinity?