Pippa Middleton tried on summery wedges and flats today during a shopping trip on the Kings Road in London. Her chic and simple style got a thumbs-up from Katie Holmes over the weekend as the actress chatted about the Middleton sisters on the red carpet for her movie Don't Be Afraid of the Dark. Pippa took a break for some retail therapy today, but she has been spending most of her time focusing on her career, friends, and fitness since the royal wedding. Pippa has successfully completed both a marathon and a duathlon since her sister's world-famous nuptials in April. She also appears to be going strong with her longtime boyfriend, Alex Loudon, despite a round of rumors that Pippa and Prince Harry are dating. Pippa is spending time in England, but her sister, Kate Middleton, will head to Canada tomorrow with her husband, Prince William, before traveling to LA. The pair will make a number of appearances in California, hosting a polo match, giving a cocktail party at the British consulate's home, and visiting an arts center for inner-city kids.