The earthquake that hit Japan last night was one of the largest ever recorded since 1900. It was actually the fifth largest so damage seen in this quake should rival last years 8.8 earthquake in Chile. Here's the list of the top 5 earthquakes recorded since 1900.
9.5 - Chile, 1960
9.2 - Prince William Sound, Alaska, 1964
9.1 - Sumatra, 2004
9.0 - Kamchatka, 1952
Here is a list of the top 15 strongest earthquakes since 1900 from the USGS website.
Tsunamis were generated from this earthquake as seen from the videos coming out of Japan. Just in the 8 o' clock hour here locally a tsunami was said to hit Hawaii but so far reports are that it has been relatively weak. I just heard a report that the waves in Maui were around 6 feet and they were happy that evacuations were ordered for the Island (source: Fox News). There are still Tsunami Warnings and Advisories for Hawaii, Alaska and the entire west coast from Washington and Oregon south to Mexico. Here are a couple links you may want to take a look at over the next few hours for the latest information.