Most conventions are about talk, but the American Institute of Architects wants to "Walk the Walk." That's the theme of the campaign recently launched by the AIA to promote sustainable design, and accordingly, the AIA has greened its convention, which this year is in Boston. No more session handouts or "Hello, my name is..." name tags. Exhibitors are packing fewer samples, and leftover food is going to soup kitchens. The icing on this eco-friendly, design-rich cake: 75 architectural tours of "America's Walking City." -KR