Yew's an incredible wood, the only part of the tree that isn't directly toxic is the red aril surrounding the seed (best not to try though), yet there's a substance in the bark, leaves and wood called taxol that can stop the spread of certain cancers and it's been used for years. The only problem is that in the tree it's in tiny quantities so you need the bark from I think 6 trees to treat just one patient (if I remember right).
It's also a rejuvenating tree, growth from one seed can last forever! Basically the branches droop down to the floor and roots grow from there, then the branch separates from the rest of the tree and so starts a 'new' tree.
But as for using it as a chopping board, I'd say it's a BIG no. In fact using it for any direct food contact is not advised.
Anthony