We call them Garage Sales here - even if the stuff is draped over someone's inner-city front fence (very few garages in my area!) or on the footpath outside an apartment block.

A Garage Sale can also be held by a group of neighbours in a small street, like the one where a friend lives. They choose a date, advertise & drape stuff over the fences & footpath, & a great time is had by all.

We also have more organised sales run by Schools or Service clubs, where folks sell from their cars, but I'm not sure how they are organised.

sandra