Tending to all-important paid promotional duties, Miley Cyrus took the stage at the grand opening of the Microsoft store in Bellevue, WA on Saturday (November 20). Making for quite the intimate affair, the gig was attended by the first 1,000 people to visit the new shop when it opened its doors on Thursday, November 18th. Meanwhile, Miss Cyrus is set to return home as she's slated to perform at tomorrow night's American Music Awards at Nokia Theatre LA Live. Airing live on ABC beginning at 8/7c, the show also features acts including Rihanna, Justin Bieber, Christina Aguilera and Katy Perry...