Based on their tweets, it seems the stars were out and about enjoying some summer sun this week. Many of our favorite music faces shared Twitpics of themselves soaking in a little sun on Twitter. 'Glee' famers Chord Overstreet and Mark Salling tried their hand at planking with their Op friends, while Sara Bareilles climbed mountains and Jordin Sparks took on the Eiffel Tower. Sean Kingston showed his face with friends IYAZ and Soulja Boy, 'Glee' star Darren Criss hung with Demi Lovato, and Zac Hanson, the youngest brother of the Hanson trio (he's 25 now), showed off his face and sweet new mustache. See what your favorite pop stars Twitpic-ed this week!