Who wears short shorts — just about anyplace? Lindsay, Nicole, Mischa, Paris and Nicky started the trend last summer, and it has since spread to the runways, the red carpet, even the office. Blame Kristen Johnson and her shorts company Johnson, a favorite with the paparazzi-trailed pack. In just one year, the designer's line has gone from being sold in three stores to 500, from being backed by her boyfriend to having a business partner.Forget denim cutoffs and Gap circa 1986 khaki Bermudas. This summer, it's all about tailored shorts, city shorts, dressed-up shorts. Whatever you call them, they are not for the beach. And what makes Johnson's shorts so special is that they are made from vintage silk, cotton, wool plaid and houndstooth, with a loose fit and a low waistband modeled after men's trousers. The legs are cuffed and fastened with one-of-a-kind buttons.