Had a similar thought a couple of days ago. Had a family death, so had to go to NY. While in the neighborhood where I grew up, I drove past the park where I would spend every night playing basketball until the lights went out at 11 pm. Most nights, the courts would be packed . . . some nights required a 30 minute wait before your team got a chance to play.
We used to play all evening, then go to the ice cream/produce market a half-block away. Numerous hot girls our age used to work there, so we would get our cups of ice water from there during our break. They closed at 9:30 pm, which meant the girls had some time where they would stop by the courts after work. You had about 15 minutes to get what you could from them inside the covered slides on the playground before they had to go home. We would play basketball the rest of the night until the lights went off.
Even though the court is much better now (glass backboards vs. fiberglass/aluminum, mesh nets vs. chain nets, a three point line vs. not having one), nobody is out there. I drove around to three other courts within a mile radius and they were all empty. One of them used to have a lot of trees/brush blocking the view of it from the main street, so it gave privacy and a bit of an uneasy/rough element while playing there, due to it drawing crime to that location. For safety/drug dealing reasons, the city removed all of that, yet the park was still empty. After going past four parks, all of them were empty . . . the only outdoor activity I saw were a lot of middle-aged joggers/walkers and two different groups of adult Indian guys playing cricket.
We did much like what others in this thread did (minus the dirtbike, ATV stuff). Besides whiffle ball, football, dunk contests, etc., we used to set up a huge tennis season that lasted several weeks during the summer. We had all of the matches scheduled. The records from that would yield the seeds for the championship tournament. All of us played sports other than tennis in middle and high school, and none of us were formally coached in tennis, but we became pretty damn good.
The other thing I notice is the lack of kids in gyms. I see a decent amount of high schoolers/college kids working out, but I rarely see middle-schoolers swimming, using the indoor gym for basketball, etc. During the cold months in middle-school, we were at the YMCA every weekend playing basketball. The bathrooms on the far side of the basketball court were great for hooking up with the 8th grade girls because the YMCA employees had no reason to walk all of the way through the basketball court to the bathrooms on the far end.
