The only time I ever spent two-and-a-half hours contemplating postal architecture, it was a few days before Christmas, and I was in a long line of holiday gift-senders. The highlight was one very unhappy-looking clerk squinting to read the small print of the postal rates chart because his computer had died right before a guy tried to mail something to South Asia via surface mail. The National Postal Museum’s Postal History Tour of Washington, D.C. should prove to be a somewhat more fruitful experience. Shuttling from the classic Georgetown Post Office to the New Deal-vintage murals at the Ariel Rios Building to the renovated, food-court accessorized Old Post Office Pavilion, the tour shows off the antique, modern, and postmodern faces of D.C.’s postal outposts. And you can send postcards between stops, too. Meet at noon at the National Postal Museum, 2 Massachusetts Ave. NE. Free. For reservations call (202) 357-2991. (Michael Schaffer)