My grand daughter is into play dates. This is a new concept for me. I seem to remember just meeting friends outside and going off to play--sometimes at some one's house but mostly just outside. Our back yard was a common place for a baseball game. There was a skating pond and a sliding hill in winter. We knew where to go to pick berries or ride bikes to the swimming hole in the summer. It being pretty much the same when my own kids were young, but I do believe as a parent I did have a better idea at any given time where they actually might be than my own parents did when we were growing up. There was a book written by Robert Paul Smith in 1957--Where did you go? Out. What did you do? Nothing.--that pretty much sums up the "don't tell" attitude of my generation.
Anyway, playing now has to be scheduled into a kid's day. You can order "parent cards" handy for handing out to other parents so that play date arrangements go smoothly. I'm sure you can make them yourself if you're into that--which I am kind of. Hey! An idea for homemade gift giving.