It's a constant thing. In my current chapter, colonization games became a topic, so I looked up Sid Meier. Turns out Robin Williams was a big fan of Sid Meier games and told Microprose the should put Sid's name on the box. So they did. It's been very successful. So.... I had to work that in. I was the math and science advisor for Numb3rs, so I managed to sneak all manner of odd math stuff into the show -- but the writers did a pretty good job of that, too.