For example, I'm on S4 of SG-1. While I was watching the episode, I found myself wondering, "What is Rodney doing *right now*? Where is John? Ronon's already running at this point, I think. Is Teyla the leader of her people yet?"
I do it for all sorts of shows. I'm also watching Due South at the moment - season two. And I find myself wondering what Ray Kowalski is doing right now, where he's at, while Fraser and Ray Vecchio run around Chicago.