Slashdot links to this story about how the brain conceives of tools: "new study in monkeys suggests that the brain's trick is to treat tools as just another body part." The researchers taught primates how to use pliers and studied the activity of 113 neurons:

The researchers first established the brain's firing sequence when the monkeys grasped only with their hands. The experiment was then repeated while the monkeys used normal pliers that required first opening the hand and then closing it to grasp the food. The same neurons fired in the same order. Remarkably, the same neurons also fired, in the same order, when the monkeys used "reverse pliers" that required them to close their fingers first and then open them to take the food.

This seems like more evidence (I'm not sure we needed anymore) for Katherine Hayles claim that "we have always been posthuman." That is, there has never been a line between human and technology, and our current technological moment is not creating a crisis of the human but merely serving to raise our awareness about what has always been.