Summer holidays for teens

I've had a wonderful day puttering in the garden, some stitching, which I haven't done since I don't know when, and reading a couple of new books in the garden.
My weekend's over, though, and it's back to work tomorrow. On the other hand, Alex will likely be up until a stupid time tonight, as summer holidays have officially started. Ah, to be 15 with little to do but enjoy! He does have a meeting tomorrow at the library about some volunteer time, and I know he really would like one of the page jobs when they come up, but they'll likely not be available until the fall, and who knows if he'll be one of the lucky ones?
My biggest worry is keeping him off electronica and having him outside every once in awhile. At 15 I just hung around, though I did work on weekends for a catering company. I'm sure I was outside all the time.
It was so easy when he was little - he could have spent the entire day at the park on the swings. I wonder what other parents of teens do? Is mine the only basement dweller??