Last Friday's Tsunami in Japen occured in the World's most technologically developed country, where everyone has a video camera. It therefore follows that the event would be recorded extensively. As geologist this is amazing. As a human being, watching a country being wiped out live on TV was frightening and horrific, to see people fight for their lives as everything around them is destroyed was truely moving. It actually reminded me watching the events of 9/11 unfold back in 2001.
The following videos are the best I found to illustrate the geological concept of what happens when a large Tsunami hits a low lying coastal plain
This is the best summary I found that shows the tsunami out at sea, then it hits the coast and moves across the coastal plain. The debris that it carries and the speed that is moves - amazing
This shows what it was like on the ground and some lucky buggars in a bus
And finally an interactive tool for doing before and after views
There is tonnes more on youtube.