This annual event will be held on March 4th, 2009 and will last as long as it is March 4th somewhere in the world. From the World Maths Day website:
Unite with students and schools from around the world to set a new world record! The Challenge – to correctly answer more than 182,445,169 questions in 48 hours.
Students play against each other in real time playing mental math games. Each game lasts for 60 seconds, students can play as many games as they wish. The questions are appropriately leveled for different ages and abilities and cover basic math facts. Of course, this is a free program, but time to register is running short. Teachers register their teams and are provided with a unique login and password for each student. When students login, they watch on a map as they are connected with students around the world to compete against.
Have fun and keep an eye out for students from a certain Math Club in Colorado.