I have started working with the wonderful Croquet software library. It lets me easily write a computer program that supports lots of people playing simultaneously in the same sandbox (things like multi-player games), without all of the fidgety extra programming that you usually need to do to support that.
I am having loads and loads of fun with it, and in my head I think of it as my shiny new toy, just like the toys I used to get when I was five years old. And that makes me very happy.