We’ve seen many times over how blogs can be a powerful communication medium. Today, Hitwise reports that the South-East Asia Earthquake and Tsunami Blog was the the 10th most visited humanitarian site last week. As we noted in this Mercury News story last week, the SEA-EAT blog was started by a blogger and communications consultant in India who was looking for a small way to aid the tsunami relief effort. It has become one of the more authoritative sources of information about the disaster and was the only blog among the top ten humanitarian web sites on the Hitwise list.