I ultimately believe that the only way we will be able to solve the Israeli-Palestinian conflict is through compromise regarding some of the biggest perpetrators of the conflict, such as claim over Jerusalem. I believe that the most fair way to accomplish a solution regarding Jerusalem is to allow it to be it's own city-state. Perhaps it could be ruled by a democratic triumvirate, representing each of the major Abrahamic religions (I believe those are the only 3 that care about Jerusalem), and a council? I am sure that both sides will complain, and one or the other may even use lethal force. I would suggest a treaty stating that neither countries are allowed to claim it and that they must recognize it's independence, and that they should do their best to defend it from other enemies. Should one of the countries invade anyway, I'm sure Allies of the other would protect Jerusalem. Of course, lots of this is very theoretical and hypothetical, however I believe it will ultimately be the best solution for the Jerusalem conflict.
If Jerusalem became a self-governing city state in a similar way to the Vatican City it would be governed by the people who live within its boundaries and Israel and Palestine would be focussed on their territories outside - there could be free movement of people and the state could be non religious allowing those faiths that see Jerusalem as a key location free to worship there in their own ways. The tourism alone would support the economy. Peace could prevail very quickly and it would not be complex or long in the creating.
I would add, this City-State would only be run Together by the Religious Leaders. The Vatican can assist in this regard. The Vatican, I suggest, use this site as a Vatican Annex.
Perhaps if this City-State could be made, then all the religions could finally have Peace in the World.