Over the course of the last three seasons, we've gotten to know the, uh, intimate secrets and details of the double life of Hannah/Belle (Billie Piper), the working girl attempting to life her life and figure out just what she wants out of it. Tonight marks the launch of the fourth and final season of the frothy and fun Secret Diary of a Call Girl and we see Belle standing at the edge of a precipice: Will she allow herself the chance to be happy with Ben (Iddo Goldberg)? Can she ever be happy or hope to settle down, given her line of work? Will she choose between personal fulfillment, professional success, or something that blends the two? As Season Four--which launches tonight on Showtime--begins, Belle finds herself grappling with a series of transformative changes in her life. She's back in London after a luxurious gig that took her far away from her life and from Ben, of whom she's still sure of what the future holds. Returning to the city, she's now a proud homeow