They tap into the rich vein of nostalgia that oozes through most Brits, who ideally would like to live in a world decorated by Cath Kidston.
Traditionally, they are sit-down affairs, with long tables running the length of the street, and everyone tucking in to such traditional British dishes as Coronation chicken and sherry trifle. But they don't have to be like that - our neighbourhood street party this afternoon featured games for the kids, a man making balloon animals and tug-of-war competitions. Plus of course a couple of bars, a barbecue, a salad buffet and a cake stall.
Miraculously, after hours of cold, grey drizzle, the sun came out for a couple of hours. What on earth did we do before pop-up gazebos?
As you can see, the dress code was vaguely red, white and blue... even for dogs.
How on earth did we celebrate anything before the fashion for cupcakes? (How on earth did we keep the kids quiet for a couple of hours before the fashion for cupcakes?)
My neighbour Ruth's dog, Minty. I suspect, from the look on her face, that Minty is a republican.