Some stars make the scene during childhood and grow into quality celebrities. Others don't get a taste of fame until they've already reached adulthood. Joseph Gordon-Levitt did both. While he got his start as a child actor appearing in alien sitcom Third Rock from the Sun he didn't actually achieve fame until he had already matured into a fine young man. Of course, before Third Rock from the Sun there was Roseanne in which Gordon-Levitt played George, DJ's equally strange friend. Total, he appeared in four episodes between a span of three seasons. Gordon-Levitt had since found his niche in independent roles such as Manic, Mysterious Skin, and 500 Days of Summer before going mainstream with films such as Inception and The Dark Knight Rises. Currently, he's working on a project known as hitRECord in which a collection of up and coming filmmakers are hired to produce their own content for the show.