I looked up lesson plan ideas with analogies for mitosis and found things I kind of liked, but nothing that really accomplished what I hoped for. I modified some of the ideas I saw and created my own analogy for mitosis, with a Prezi titled Soccer Team of Twins--a Mitosis analogy. The guided notes are available from a link in the lesson plan.
I also extended this into Meiosis with modifications to apply the same analogy to germ cells. See Soccer League Divides Players into 4 Teams--a Meiosis analogy for Prezi