Zac Efron, the lead from "High School Musical" TV and movie hits, will have young girls' hearts fluttering this afternoon at the Mall of America. Efron is starring in a new movie, "Charlie St. Cloud," a tear-jerking romance about a young man torn between his new girlfriend and the memory of a younger brother who died. Efron will be answering fans' questions and signing autographs. He is scheduled to arrive at the Best Buy Rotunda at 2:30 p.m. His new movie opens nationwide on July 30.