You hear a lot of talk these days about dressing down, about life in a less formal culture where clothes play a more casual role in defining who we are and where we are going. For most women, the change is welcome andliberating. Dressing down saves precious time and money. It helps create a more comfortable setting and a more democratic contect for work, one in which we are judged on the basis of performance and not on the length of our skirts. So where's the hitch? Is there a hitch?