But whether refugee or banker, militant or moderate, they all share the dream of one day returning home. They are Palestinians in the diaspora.
The word most often used by Palestinians to describe their fate is ghurba (exile). In Arabic the word conveys the meanings of both stranger and outsider, a reflection of how - more than any other experience - exile has shaped Palestinian identity and values. The sentiment is most eloquently expressed by Fawaz Turki in his book The Disinherited.
'If I was not a Palestinian when I left Haifa as a child,' Turki wrote, 'I am one now. Living in Beirut as a stateless person for most of my growing years, many of them in a refugee camp, I did not feel I was living among my 'Arab brothers' . . . I was a Palestinian, and that means I was an outsider, an alien, a refugee, a burden.'
Although records are not precise, because many Palestinians carry documents from their adopted countries, it is estimated that today 60 per cent of the Palestinian nation lives outside Israel and the occupied territories. The majority, about 2.5 million, live in Jordan, Lebanon and Syria; the remaining million or so are evenly split between the other Arab states and the rest of the world. Most fled Israel in 1948, a time that Palestinians refer to as al-nakba (the catastrophe).
For 46 years, these Palestinians have kept alive the dream of returning to their homes, and have passed on to their children and grandchildren the passionate conviction that there was no life without the land. So now it is not easy for them and their heirs to acknowledge that their dreams, like their houses, are lost forever.
But that is what many have had to do in the wake of this week's historic agreement between the PLO and Israel on Palestinian autonomy in Gaza and around the West Bank town of Jericho.
Even the return of Palestinians who fled the 1967 Middle East war - a slightly less contentious issue in Israel - is now in doubt after Friday's announcement by Israeli Prime Minister Yitzhak Rabin that Israel was not bound to allow these people back into the country.
Many diaspora Palestinians feel that they have been sacrificed by the Palestinian leadership in order to gain a foothold in Gaza and Jericho as the first step for some eventual Palestinian entity on the rest of the West Bank.
'The sad thing about the agreement is that there is no mention of the diaspora. They seem to have been ignored,' said Said Aburish, a Palestinan journalist and the authour of The Children of Bethany, a book about his own family's experiences in Palestine and throughout the world.
Though vague promises have been made that 1948's refugees will not be forgotten, Mr Aburish believes these Palestinians have been disenfranchised. 'The only question is who is going to adopt them now? According to Dr Abbas Sheblak, an academic working on a study of the Palestinian diaspora, the likelihood of an Arab country now sponsoring the Palestinian exiles is slim.
'The condition of Palestinian refugees in Arab host countries has deteriorated since the signing of the Declaration of Principles between Israel and the PLO in September last year,' Dr Sheblak said.
'Many Palestinians have lost rights and freedom of movement in some countries, while in Lebanon there has even been talk of expelling refugees . . . they are being used as a way to put pressure on the Palestinian leadership and the big powers to do something about them.'
This is not the first time that Palestinans have been used as bargaining chips or forced to become second-, third- and fourth-time refugees. The post- 1948 history of Palestinians is like a never-ending trip from hell. They have moved into and been expelled from nearly every Arab country that has opened its doors to them.
No wonder Palestinans feel vulnerable. Subject to the dictates of bureaucrats, prone to disasters and humiliations, dependent on the whims and internal politics of their host countries, they lead dual lives as refugees and terrorists, victims and victimisers.
Ironically, the success of the Israeli-Palestinian agreement on Gaza and Jericho may depend on the willingness of wealthy exiles to invest in the project.
One wealthy Palestinian in London said that, given the uncertainty of the future of the deal, any Palestinian investment will be 'discretionary and token', aimed at a quick proit and of little real benefit to the local people.
However, Adel Dajani, the managing director of private merchant bank London Court Ltd, disagrees. There is, he says, among diaspora Palestinians in particular a cautious optimism over the new agreement.
Although it may mean that many Palestinians will never go back to the land of their origin, 'it is a pragmatic step in the right direction, and it is unreal to expect all things for all men right now. While there are many questions dealing with business law and security, we in the diaspora cannot allow ourselves to be passive witnesses.
'After more than 40 years outside, we have to use our capital and management expertise to make sure this is a positive first step.'