That '70s Show—From the wide-leg trouser to the sexiest classic halter top, the '70s are back (again!) in a big way.Above, from left: The '70s trend on the spring 2011 runways at Marc by Marc Jacobs, Marc Jacobs, Derek Lam, and Tory Burch.Above, from left: The '70s trend on the spring 2011 runways at Marc Jacobs, Jason Wu, Thakoon, and Rodarte.The Return Of Minimalism—Phoebe Philo started it at