Also a good past-time for a humanist: Stopping Jews from building walls that protect them from terrorists.
It's much cheaper and safer than protecting Africans from being slaughtered in the Sudan and certainly beats protesting against Saddam for the right of Kurds not be gased. Worst thing that could happen is a night or two in an Israeli prison (which can be complained about for years afterwards).
Yes, stopping the Jews from building walls that protect them from the fate of other non-Arab peoples in the region is definitely a step towards a better world.
And the best thing is, if something happens to the humanist while he is in Israel, protesting its existence and relative security, Israel has some of the best hospitals in the world and is always willing to help.
Another tip: Fly in via Ben Gurion. It's more comfortable than Amman. It is one thing to protest against Israel, but it is quite another to live one's life without using what Israel has to offer.