Hayek helps Baldwin get the party started on the Brooklyn, N.Y., set of 30 Rock. Plus: Charlize Theron, Joe Jonas, Gisele and more

'MAC' FACTOR

Kim Kardashian – who said she'd "totally go back" to Dancing with the Stars to replace injured contestant Misty May-Treanor – is ready for the call after picking up some makeup essentials Thursday at a MAC store in West Hollywood.