GRAND JUNCTION, CO—Marnie Powell, a seventh-grader at Grand Junction Middle School, lied to her diary Monday, filling the journal with several out-and-out fabrications. "I had the best time at Jessica's party," wrote the 13-year-old honors student, recording the falsehood in purple ink. "There were tons of cool guys, and I had so much fun dancing." In actuality, the socially awkward, bespectacled Powell tentatively bobbed up and down on the perimeter of the dance floor for 30 seconds before retreating to the refreshment table for the remaining three hours of the event.