Back in the Old World, Naples at Christmas time conjures up its own kind of kitsch. Stroll among the boutiques of the Via San Gregorio Armeno, in the heart of Spaccanapoli, and you'll find any number of presepi, or Christmas Nativity scenes, for the taking.
Chances are, Mary, Joseph and Jesus will be in a gaudily decorated sitting-room against the backdrop of Mount Vesuvius, accompanied by anachronistic mini-sculptures of Italian politicians, football players and the occasional Hollywood movie star. Some presepi will even have salami and mozzarella clusters hanging off the ends.
Here in the New World, in Naples, California, the cultural terms of reference are a little different but the gaudiness remains intact. The big attractions here may lack artfulness but are considerably more glittery: lights upon lights, literally thousands of them, along with window displays of Santas, Christmas trees, sleigh-bells, fake snow and stuffed Winnie-the-Poohs decked out in winter garb.
Above one house, the words "Oh Joy" are spelt out with hundreds of bright white light bulbs, each "O" revolving in the night sky like the lettering on a Las Vegas casino marquee. At another, the front garden has been turned into a fantasy funfair peopled by characters from Disney cartoons and Saturday morning animated serials. A homemade rollercoaster ride, with tracks made from pieces of balsa wood, makes improbable playmates of Mickey and Minnie Mouse, Dipsy and Po from the Teletubbies, and ET, who all spin around the track together.
Yet another house has devoted itself entirely to the theme of The Nutcracker, with Tchaikovsky's music playing softly over an external music system and full-size toy soldiers standing guard alongside.
Naples is far from the only enclave of such all-American seasonal excess, but it is almost certainly one of the most enjoyable. It is a man-made island in Alamitos Bay, just to the east of the enormous docks of Long Beach, a maze of canals criss-crossed by elegant bridges and lined with well-appointed houses. A welcome exception to the relentless sprawl of greater Los Angeles, it was designed to be walked around – a self-conscious attempt to recreate an Italian atmosphere on the shores of the Pacific, with a tradition of evening strolling and gondola rides. (Naples, Venice ... they all seem the same from 7,000 miles away.)
The inherent theatricality of the place makes it a natural setting for Christmas time stagecraft. The living rooms and front yards of the million-dollar homes are, in their way, like lifesize presepi, with every Merry Christmas cushion and stuffed toy placed just so for the benefit of the passing visitor. Strings of lights snake up neo-colonial colonnades to resemble giant whirling red-and-white candy canes, and rooftops scream out political or religious messages – everything from a multi-coloured "Jesus Saves" to a light-bulb Stars and Stripes flag.
The show goes on every night in December. Parties quickly become communal affairs, as gaggles of roving local teenagers mingle with dowdy matrons wearing giant plastic Rudolf noses.
At one Scottish-themed party, grown men sported kilts and Santa hats without a hint of self-consciousness.
Naples has been holding its Christmas festival for just a few years – it sprang out of a winter gondola tour – and it has grown sophisticated enough for artificial Christmas trees festooned with lights to be positioned at strategic intervals in the bay.
In fine American fashion, though, it is predominantly a private enterprise affair, not a civic initiative: nobody has to be told to turn their property into a winking multi-coloured fruitcake, much less to spend thousands of dollars on extra electricity.
In similarly American fashion, it is less about old-world artistry than it is about brandishing symbols of consumerism and national pride.
So it goes across the country. Less than 30 miles away, in the foothills of the San Gabriel mountains, the city of Altadena boasts a Christmas Tree Lane where 135 deodar cedar trees stretching over three city blocks are strewn with 10,000 lights.
In San Francisco, a famous house seeks to outdo itself year after year as the front garden is piled high with gift boxes, sleighs and giant figurines of reindeer and children in hats and scarves.
In Austin, Texas, a 153ft all-electric Christmas tree – not so much as a twig is real – claims to be the tallest of its kind in the world.
In Sarasota, Florida, a private ranch boasts dancing Christmas trees that change colour in time to seasonal music. Also in Florida, a house in St Petersburg boasting 250,000 twinkle lights, 500 animated figures and a 70ft tree made headlines last year because the owners chose to give it a rest in deference to the victims of 11 September.