It’s art week in New York: The Frieze Fair is in full swing, the galleries are pulling out the big guns — or in the case of Gagosian, the big balloons. And everywhere, everyone seems to be heeding the call of curator and all around art instigator Hans Ulrich Obrist to Do It. Obrist’s premise: create an instruction that someone else can use to make an artwork. (Perhaps the artist Paul McCarthy, whose enormous red balloon dog practically dwarves the Frieze tent, which is the biggest in north America, on Randall’s Island, read Jeff Koons’s entry?) Last night W Magazine and Burberry celebrated the publication of a compendium of 20 years of doing it with a dinner at the Park Avenue Armory. It’s always fun when the fashion and art worlds collide. Obrist summed it up best, quoting from Louise Bourgeois’s do it proposition: When you are walking, stop and smile at a stranger.