There's a "national ideas competition" happening on The Washington Monument Grounds:

Its purpose: to encourage Americans of all ages to develop innovative and creative ideas for making the Washington Monument grounds more welcoming, educational, and effectively used by the public. The idea for this Competition came out of a realization that while the Washington Monument is the defining feature of the Washington DC skyline and the centerpiece of the National Mall, at ground level its vast open space remains unfinished and underutilized. Currently, there is no consensus as to what role the Monument grounds should play in the future. The Competition will spur public interest in George Washington, the Revolution, and other chapters in the American story. The Competition will join legacy and future, historical context and contemporary thinking, and engage a lively debate about the 21st century use of this symbolic landscape in the civic life of our democracy.

On the Champs de Mars you can buy beer from vendors. But I have a feeling that idea won't be winning any competitions in the United States.