Shia LaBeouf donned a suit, but no tie, as he headed into The Late Show With David Letterman's studios today in NYC. The actor, who sported a sleek pompadour for his TV appearance, is back in the states after spending part of last week in Europe. He joined his fellow cast members for the Russian premiere of Transformers: Dark of the Moon on Wednesday before the group split up to tackle press duties in Madrid, Berlin, Paris, and London. Shia was also profiled in yesterday's Los Angeles Times and talked about both his career and his romantic life in the interview. Shia's girlfriend Karolyn Pho was one topic of conversation, and he admitted that his new love is encouraging him to be more grown-up and adventurous in life. On the big screen, though, Shia's only got eyes for Rosie Huntington-Whitley, who replaced Megan Fox in the third installment of the action franchise.