World Vision, a Christian aid organization akin to Compassion International, is rallying support for the Child Soldier Prevention Act of 2007 (S. 1175), composing a message that will be sent to your senators and congressmen for you urging them to support this bill.
World Vision's site will identify and contact the representatives for you, using you Zip Code, so all you have to do is take 30 seconds and fill out some contact info for them to do this with. Personalize the message if you like, or you can simply send it as is.
I can think of NO better way to spend 30 seconds, can you?
I've already had this sent to my senators and would encourage everyone reading to do the same. This is a small step that you can take in the fight against the legion of injustices that plague our world.