Rapper and actor Ludacris posted a sweet and heartfelt throwback thursday photo to his instagram today. The picture was of him and the late Paul Walker. It was a snapshot of them on a break while filming Fast and Furious 6. In the photo, Walker is holding Ludacris's pet dog. He put as the hashtag, "when I see you again." A few weeks ago he posted another photo of Walker with the hash tag, "gone but never forgotten."