Please vote in the Peace Primary. From their Web site:
Twelve groups promoting peace. One will win $100,000 to amplify their message in the 2008 election. You decide. The Peace Primary is your chance to ensure that the peace issues you care about are a priority in 2008.
Personally, I recommend voting for the Genocide Intervention Network, but whom you vote for is up to you. This is a good cause, so get to it!