Kardashian and her 21-month-old son enjoy some mommy-and-me time in N.Y.C. Plus: Gwyneth Paltrow, Mary-Kate & Ashley Olsen, Pink & Willow and more

HAPPY FEET

On-the-go mom of two Tina Fey boogies to her own beat Wednesday while filming the latest season of 30 Rock in New York's Rockefeller Center.