Last year we grew a huge pumpkin vine from one seed. (I'm - somewhat unsuccessfully - attempting to grow pachysandra in that space this year, so we skipped out on pumpkins.)
Right about this time of year last year when the pumpkins were about the size of softballs I took a nail and lightly scratched the kids' names on them. Just deep enough to gently break the skin.
Come October when we harvested them, everyone had their very own personalized pumpkin on Halloween!