Seated along the rim of the fountain in Rome's Piazza in Spagna, the dark-haired boy and the blonde teenage girl eyed each other uncertainly. "What do you want to do?" he asked shyly. "I don't know. What do you want to do?" she answered demurely. And then, suddenly, there were two minds with a single thought. "Why don't we go to Piazza Novona for an ice cream?" they burst out almost in union. And, rather pleased with themselves, they climbed on to his battered motorscooter and headed east.

In the Roman spring and summer a young person's fancy turns - among other things - to ice cream, most of it homemade- It isn't that gelato , in either its packaged for homemade forms, isn't available all year round. But going out for an ice cream has long been considered a pleasant and inexpensive way of passing a lazy summer afternoon or a stifling-hot summer evening.

Couples with limited means, poor families whose numerous offspring make an evening at the movies hard to afford and well-heeled types bored with all kinds of indoor recreation, as well as with each other, can all find solace in long evenings at tables outside one of Rome's 870 gelaterie , or in leisurely cone-licking walks against the theatrical backdrop of ancient and medieval Rome.

"Baskin-Robbins, eat your heart out," an American from California said the other day while avidly devouring a chocolate-covered tartuffo at the Tre Scaline bar in Piazza Navona. "Howard Johnson's can keep their 28 flavors," she added. "How can home production ever compare with ice cream under a Bernini statue, before a view of 'Rome-by-night' or in the shadow of the Colosseum?"

But above and beyong the visual bonus offered by Rome, is the fact that Italian ice cream - sometimes mediocre but never bad - is usually very good.

Italian ice cream (not to be confused with the water-based, sherbet-like Italian ices sold in Italian vast range of flavors that seems to include almost every fruit known to the West, and then some.

The 20 to 30 flavors stocked by Rome's 100 creme-de-creme gelaterie - and their counterparts in other major Italian cities - now many include fruit flavors as various as melon (canteloupe), watermelon, orange, lemon, blueberry, blackberry, raspberry, starwberry, plum, grape, apricot, tangerine, grapefruit, peach, cherry, sour black cherry, pear, pineapple, banana and even fig, prickly pear and persimmon.

These, of course, are merely additions to classic Italian "creme" ice creams such as chocolate, gianduya (from a chocolate-drop speciality of Turin), vanilla, coffee, pistachio, hazelnut, almond, walnut, torrone, rum crunch, zabaglione, coconut and a range of varieties made with extra cream or other additives including whisky or Cognac.

There are also other specialities: The granita of coffee, lemon or gianduya made with grated ice and topped with a whipped cream; the semifreddo slab of ice cream served with sour cherry or hot chocolate sauce; or the Mela Stregate (bewitched apple) created by the Biancaneve or Snow White gelateria and the by-now famous Tarfuffo sold at both Piazza Navona and at Ciampini in via Franttina.

But the most notable aspect of Roman ice cream is that like Italian gelato in general, most of it is homemade. Only one-fourth of the ice cream sales in Rome, in fact, go to the makers of pre-packaged preservative-laden ice cream that Italians call "industrial" in contrast to the handiworked or artisan-made type.

"This is quite a turnaround," says Alberto Pica, the president of the Rome association of ice cream parlors and coffee bars, who owns a small gelateria in downtown Rome. Before World War II, he explained, the only kind of ice cream in Italy was the homemade variety.

But after the second World War the American influence led to switch over to the industrial type. People got used to pre-packaged Dixies, cones, popsicles, sundaes and sandwiches. During the 1960 Olympics, home-production had a chance to flourish and the trend reversed itself.

At the point, Pica says, homemade ice cream makers got together and "We spruced up our bars and parlors, improved production methods and hygiene, and started using our imaginations." The result was that Italians started to return to the fold." At first slowly," says Pica.

The triumph of homemade over pre-packaged - now 70 per cent to 30 per cent in Italy as a whole - is easy to understand for anyone who has done some extensive though non-scientific smapling. Pica briefly demonstrated these superiority of artisan-made ice cream by filing two 120 gram glasses, one with industrial and one with homemade chocolate. Then he weighed them. The homemade weighed 120 grams. The industrial, which Pica says has been whipped more and contains more air, weighed considerably less.

"This means," he said triumphantly, "that homemade ice cream is more nourishing as well as more tasty. It also doesn't have the additives and artificial colorings that the industrial type has to use if it's going to market its product nationally."

The best gelaterie in Rome use superior ingredients, avoiding pre-prepared flavor pastes which vary in quality, and rely on family secrets that they believe make their products something special. "Our ice cream maker is a grizzled worker who's been with us for over 40 years," one owner said. Standardization has therefore taken place only in terms of methods.The taste varies from ice cream parlor to ice cream parlor.

While the visiting ice cream freak will have to sample around, anyone who has been in Rome for several years has developed a good idea of the best ice cream parlors in town. My favorites are Giolitti in Via Ufficio del Vicario, Pignotti in Via Buoncompagni, Tre Scalini at Piazza Navona, Ciampini in Via Frattina, Bernasconi at Largo Argentina, Bianca Neve in Piazza Poli, Pica in Via della Seggiola, Ottaviani in Via Leone, Vanni in Via Cil di Lana, Ottaviani in Via Babbuino, Torpignatara in Via Briga and Piazza in Via di Villa San Filippo.