I have a basic javascript implementation of a mega-menu here http://minimul.com/because-mega-dropdowns-are-better.html http://minimul.com/because-mega-dropdowns

I have a basic javascript implementation of a mega-menu here http://minimul.com/because-mega-dropdowns-are-better.html http://minimul.com/because-mega-dropdowns-are-better.html . Yes, by default it does columns, however, it also has an option for doing rows.