These days I'm planning more activities for playdates, versus just having kids over to play (aka tear through the house). Three year olds have so much energy that needs to be directed somewhere, at least for a few minutes.
Last week we had some friends over to bake bread...I had the dough ready when the kiddos got here, then they all got to shape their own loaf. The bread rose and baked while they played, then everyone got to take their loaf home (actually I think most of it was devoured on the spot). YUM!