This is a new organization (founded September, 2008) that has the right idea. Click the title to this post to learn more.
Also, click here to sign their petition to Israeli soldiers re: Gaza, reprinted below:
I'm not completely comfortable with the ethnic self-interest argument above, but it's designed to appeal to the best in less cosmopolitan Jews, I imagine.
Open Letter to Israeli Soldiers
If you are Jewish, please sign the following statement, which we hope to be able to publish soon in Israeli newspapers. Donations to help pay for publication can be sent via PayPal by clicking here.
We encourage organizations to sign by sending us email.
Jews call on Israeli soldiers to stop war crimes
We Jews in the international community call upon Israeli soldiers to raise the Black Flag of Illegality over the operations against the people of Gaza.
We refuse to remain silent while Israeli leaders force Israeli soldiers to commit war crimes: crimes against humanity for which they will one day be called to account. Israeli soldiers of conscience can, and must, stop this dangerous, illegal, and immoral war.
This criminal activity does nothing to advance the health and welfare of Jews. Rather, from Sderot to Sydney, from Ashkelon to Amsterdam, we will all benefit when there is justice for Palestinians.
Therefore, we call on you to use all measures possible to stop these atrocities against the Palestinian people. Flagrantly illegal orders must not simply be disobeyed, but actively and effectively opposed.
We members of the international Jewish community call on you, the Israeli soldiers of conscience, to halt the Israeli war machine, which only you can, and must, do.
Signed, (Add your name)