CINCINNATI, June 18 /PRNewswire-FirstCall/ -- In anticipation of the first day of summer on Thursday, June 21 -- and the hot weather that comes with the season -- Old Spice today announced its Sixth Annual Top-100 Sweatiest Cities List. For the fourth time in six years, Phoenix burned up the charts to take the No. 1 spot in this annual ranking of the nation's heaviest sweaters. To earn the top spot, Phoenix's average high temperature was 94.6 degrees in June, July and August 2006, resulting in the average Phoenix resident producing 26.3 ounces of sweat per hour. That means on...