Retired people: what have you done to keep busy?

I had to call customer service the other day and found myself talking with a delightful woman while we waited for her computer to look up various bits of information. She mentioned that she had actually retired several years ago and that taking calls was just something to keep her busy for a few hours a day that she didn’t have to worry about when she got home.

If you are retired, what did you take up to keep busy? Did you get a job of some kind? Volunteer work? Something else entirely?