He entered this year's American Idol season too shy to answer Ryan Seacrest's inane post-performance questions, which endeared him immediately to swooning girls and their moms. He played a mean guitar, and his wistful performances of "Over the Rainbow" and "Hallelujah" solidified his standing as the sensitive crooner in the competition. By the time he exited in fourth place, Castro, 21, had made dreadlocks family-friendly and ukuleles cool even if we all promptly forgot about him because of those two dueling guys named David.