1) Sit down and ask your grandparents or parents about your relatives and about family stories, draw up a tree with details about each person. Sit down for the stereotypical kid-interviewing-grandparent-for-a-school-project-but-becoming-really-interested afternoon. Sadly, they won't be here forever. Take advantage of the time they're here for.
2) Every once in a while go through your contacts. Anyone you haven't talked to in a while, shoot them a quick email, text, or even call them. Catch up with everyone. You never know when they might need just that- a friendly message out of the blue. You won't even realize that's what you really need too!
Have a great holiday tomorrow everyone!