As I mentioned last year, many parks in my area have a tree that people decorate year after year. There's no formal process or rules. People just show up and add whatever they want.
I love seeing what people come up with each year, although I worry that some of the ornaments won't do so well in the rain.
Here are this year's photos.

This is the side of the tree that faces the trail.

Close up of the tree. Those round lights were blinking, but I couldn't see a power source.

This year a few toy soldiers made it onto the tree.

Here's another toy soldier.

Back side of the tree. I'm not sure what to call that golden Japanese ornament, but I think it's really cool.
How about your neighborhood? What interesting decorations have you seen this year?