The holiday season is pretty busy for the United States Post Office -- lots of letters and packages going all over the country, from coast to coast. And we're all familiar with the warnings that tell us to mail our items early if we want to guarantee delivery by Christmas. Well, apparently D.C. residents weren't heeding the warnings back in 1921. So the U.S.P.S. called in the big fella to get the point across. Here's Santa in a "post office a la carte" truck decorated with appeals for early mailing during the Christmas season.