Alexis Bledel showed off her new engagement ring from her fiancé, Vincent Kartheiser, at the premiere of her new film, Remembering Sunday, in LA yesterday. The bauble features a large round-cut diamond set in a platinum band. She told reporters at the event that Vincent picked out the bling but their wedding planning will be a joint effort. Alexis said, "We're doing it together. We haven't started yet though." The couple announced their engagement back in March after dating for nearly a year. Alexis and Vincent started their romance after playing onscreen lovers on Mad Men.