What might the future hold for the humble postal stamp? The financially challenged U.S. Postal Service is paying a New York consulting firm named Faith Popcorn’s BrainReserve more than a half-million dollars to find out. “Who will be buying stamps in 2019, 2024 and 2034? What will they be used for?,” reads the company’s description of the $566,000 task order awarded last month. “How can we embed innovation and new thinking into stamps, to engage America’s coming generations and the [USPS’s] existing and new customers?” After starting the job early last month, BrainReserve–whose website touts its consulting specialty as “applied futurism”–is…