From what I gather it was some sort of idea for an amicable settlement between Jews and Arabs in Palestine and somehow involved [Ibn Saud][1]. [Weizmann][2] and Churchill apparently supported it but Ibn Saud shot it down. 

But this is very vague and [Wikipedia][3] is absolutely unclear on this.


  [1]: http://en.wikipedia.org/wiki/Ibn_Saud
  [2]: http://en.wikipedia.org/wiki/Chaim_Weizmann
  [3]: http://en.wikipedia.org/wiki/St_John_Philby#Philby_Plan