Since everyone across the country is repeating the phrase, "Who is John Galt?", it is naural that many people have attempted to answer that question. Dagny Taggart hears a number of John Galt Legends before finding the real John Galt.
There is a clothing store at 193 Gore Creek Drive, Vail Village, Colorado called John Galt Ltd. One presumes that, on occasion, a customer unknowingly walks in and asks, "Who is John Galt?"