Thunder over Louisville takes place every year 2 weeks before the Kentucky Derby. It consists of one of the largest air shows in the country and the largest fireworks display in the country. For the past year there were 55,000 shells detonated in just 1 half an hour.
Each year I try to position myself next to people who have never seen it, just to see their jaws drop and the look of delight on their face.
For 2008 it will take place on the 12th of April.
thunderoverlouisville.org/

By the way, this was the first use of my Sony H3 HD recorder so be kind :-)