Both The New York Times and ABC News have published before and after satellite imagery of the destruction caused by the Japanese earthquake and tsunami. Both visualisations use new imagery captured by the GeoEye satellite.
Google are working to provide this data directly to response organizations on the ground to aid their efforts.
From ABC News
From the NYT
You can donate to the Japanese Red Cross Society here. You can also donate to the Japanese Red Cross with Google Checkout at the Google Crisis Response website.