Like you, I'm sure, I've had my eyes glued to the news about Japan.
I think our only real response can be from the sense that it could be us. That could be me.
Therefore I grieve for families, for the husband found riding on a rooftop after he lost his wife, for parents and for children. For all the smallest things, even: The favorite coffee shop, the lost routine. The big things, even for people who haven't lost family: The loss of a sense of safety, or the sense that the earth is stable.
My response is sadness and prayer. Thoughtfulness in my life. Giving. May I waste nothing. Not one moment, not one ounce of boring contentment. May we be thankful for everything we have, knowing that it could have been us, that it could be us, that nothing is assured, nothing within our control. All we control are our own responses.
May our response to life be with big-heartedness, compassion, and contentment.