There are more than 10 million Palestinians living around the world, more than half of whom are stateless. In this year when Israel has been marking its 60th anniversary many Palestinians have been reflecting on the event that for them meant exile. The 'naqba', or catastrophe, is how they describe the destruction of many of their villages and towns and their own dispersal following the creation of the state of Israel in 1948. For Assignment Paul Adams spoke to four Palestinians in exile.