To show how big was the huge tsunami that happened last friday in Japan, the New York Times has published an interactive page with aerial photos, where you can compare what happened after the tsunami in the cities of Ishinomaki, Natori, Sendai, Yuriage, Arahama.
The sight is terrible, and is available here:
www.nytimes.com/interactive/2011/03/13/world/asia/satellite-photos-japan-before-and-after-tsunami.html
Update: There's also a Picasa album with more shots, and a kml file to see the area with Google Earth.