Women in Black was founded in Israel in 1988, in response to the 1st intifada which began in 1987. It's now an international organisation with vigils in many different countries and for various issues. For example, in the US women protest against the war in Iraq; in Colombia they protest against drugs and violence. Details of international Women in Black groups can be found here.
It is also part of the Coalition of Women - a coalition of 9 women's peace groups in Israel who are looking for practical solutions to the situation there.
We demonstrated with the women for over half an hour, standing with signs saying "End the Occupation" in English, Arabic & Hebrew. We saw people who were pleased to see us, angry to see us and people who simply ignored us. One guy on a motorbike stopped so he could buy a badge. The passengers in one car wound down the window so they could yell "f**k off!" at us. It always seems to be one extreme or the other.