If you don't know what a Harlem Shake is yet.. Youtube it. There are thousands of videos on there 
of people doing this. Everywhere.. underwater, army edition, schools, celebrities. Everyone is doing it!
Our uni came up with the idea of doing this the other day and weirdly for the
first time ever something in our uni worked out. I am somewhere in there! haha
Have a look :) (change it to the highest quality).