On the morning of Sunday, September 11th 2011, I will be drinking coffee with sugar and cream and eating a croissant. I will do this in commemoration of the victory of the Holy Roman Empire and the Polish-Lithuanian Commonwealth over the Ottoman Empire near Vienna on September 11th, 1683.
Wikipedia: Battle of Vienna Culinary Legends
Several culinary legends are related to the Battle of Vienna. One legend is that the croissant was invented in Vienna, either in 1683 or during the earlier siege in 1529, to celebrate the defeat of the Ottoman attack of the city, with the shape referring to the crescents on the Ottoman flags. This version of the origin of the croissant is supported by the fact that croissants in French are referred to as Viennoiserie, and the French popular belief that Vienna-born Marie Antoinette introduced the pastry to France in 1770. [...] After the battle, the Viennese discovered many bags of coffee in the abandoned Ottoman encampment. Using this captured stock, Franciszek Jerzy Kulczycki opened the third coffeehouse in Europe and the first in Vienna, where, according to legend, Kulczycki himself added milk and honey to sweeten the bitter coffee, thereby inventing cappuccino.
I might have a side of bacon, too.
See also Trevor Blake: 9/11 Timeline.