Silent lawn appliances (leaf blowers / mowers) could be invented
Backyards could have potlucks
Hot tubs / pools in backyards could be open to all
Cats could have "catios"
Pools / hot tubs could be inflatable
Roller coasters could be pedal-powered
Fences / walls could turn into tables
Animal obstacle courses could be built in backyards
Backyards could be rented
Film festivals could be held in backyards
