http://www.cs.ubc.ca/nest/imager/con.../KnotPlot.html
Wander on down to the Downloads section and grab it, it's a freeware... thing. It makes real pretty pictures based on knots, with some kind of high-end math I'm not familiar with running the show. I'd recommend starting off in Demo B or Demo A, and pay attention to the text bar at the bottom for fun things to do with each design. You can rotate most designs with the mouse, too.
James
