I recently found out that Leuven, Belgium has trumped Cincinnati, Ohio. In 2007, Epybird, the two guys that orchestrate mentos geysers, turned Fountain Square into more than 500 bottles of simultaneously shooting Diet Coke.
On April 23, 2008, a group of Belgian students donned blue raincoats, and, with the help of Epybird, turned Ladeuzeplein Square in Leuven into a mentos Diet Coke mess. It’s reported that 1,360 people participated in this latest Guiness World Record-breaking endeavor.