Just found this site after many years of reading Larry Niven's work. As a motion graphics designer in London I've always wanted to visualise the Ringworld. Hope you like the links!

The Ringworld: http://www.youtube.com/watch?v=sR2296df-bc&feature=channel_video_title

Ring Walls & Spill mountains: http://www.youtube.com/watch?v=PJIwruvheLA&feature=channel_video_title

Great Fan site people!

Simon.

PS: Apologies if i've listed this link in the wrong section....