It appears a huge meteor has just struck somewhere over Russia. Phil Plait is posting frequent updates over twitter. What is amazing is how many cameras seem to have caught the entry, and subsequent breakup, of the meteor. In Russia most cars have dashboard cameras installed to collect evidence in case of accidents. There are some crazy videos of Russian driving on Youtube, but this is the most awe-inspiring dashcam footage I have seen yet.
Also, check out this video shot after the meteor passed by. About 20 seconds in you can hear the awesome sonic boom caused by the meteor's entry
UPDATE: Phil Plait has posted a more in depth analysis of the meteor strike, including some impressive footage.