We have taken the following text directly from the RunforJapan.com homepage, as we can't say it any better:

A massive earthquake, the seventh largest recorded in history, struck the east coast of Japan on Friday the 11th of March 2011. The earthquake, measuring 9.0 on the Richter scale, triggered a tsunami which hit the east coast of Japan with 7-metre-high waves, leaving a trail of destruction.

With a death toll in the thousands, an economic cost in the billions, and the threat of nuclear meltdown imminent, the people of Japan face their greatest disaster for decades.

Inspired by Japan's great runners Run For Japan is about bringing together the global running community and showing solidarity and support through dedicating runs around the World to the people of Japan.

The challenge...

To cover 24,901 miles (right around the world) in 28 days with at least one run dedicated from every country in the World. To achieve this runners around the globe are being asked to dedicate just one run to the people of Japan and donate at least one unit of their home currency per mile run.

So, how can YOU Run for Japan?