BUTTERFLIES BEFORE GAMES: A horizontal perspective on swimming inspires new Olympic-theme outdoor advertising from Speedo and The Boston Globe. Authentic Fitness Corp.'s Speedo, a 1996 Summer Olympics apparel licensee, is using tha t tie to the Games as the platform for its biggest ad campaign ever. Spending is said to be in the $5 million to $10 million range. The campaign also includes print and TV via Jerry & Ketchum, New York. The ad for the the Globe pro motes its Olympics coverage. Ingalls Advertising has its athlete plying through an actual column on swimming.