Tank tops, flip-flops, bare flesh and cleavage. It's the unofficial uniform of the summer interns, gaggles of college-age women and recent graduates who invade buttoned-down conservative Washington every summer, bringing a large dose of hotitude to offices from Capitol Hill to K Street. They're known as "skinterns." Those who think "belly shirts" are career wear. If the devil wears Prada, the skinterns wear nada. As if Washington wasn't sweltering enough. "All the guys I worked with here, they would love it when the weather got warm for that very reason. 'Ooohhh, the interns are coming,' " said Elizabeth Conatser, a...