You may seek funding from your local Jewish Federations, synagogues or other local donors to help offset expenses.

United Jewish Communities of North America
http://www.ujc.org/section.aspx?id=5
The UJC represents 157 local Jewish Federations and 400 independent communities across North America. Use their convenient search engine to find the Jewish Federation that serves your community. Jewish Federations typically have donations and endowment funds specifically allocated to Jewish residents who want to take trips to Israel. Search your Foundation website for links or emails to scholarships.

The Foundation for Jewish Philanthropies
http://www.jewishphilanthropies.org/israel_scholarships.html
This organization's mission is to ensure the continuation of Jewish life. They have many endowment funds that you can apply for.

Synagogues
If you belong to a synagogue, definitely give them a ring! Often, synagogues have set aside funds specifically designated for sending local teens to Israel. Call your synagogue's office to learn if they offer this type of scholarship.

There are many other random scholarships available to young Jews - so get creative and search around. You never know unless you try!