The art and science of mixology has brought the cocktail into its own, and bartenders here and across the country are updating the classics. Commercially infused spirits have expanded the bartender's flavor palette, and classics like the Rickey, the Old Fashioned, and the Collins have been elbowed off the menu by a hip new generation of Technicolor treats. Some old standbys remain, like the Negroni (below); others have been reinvented by local watering holes. Here are some favorites:

Gin fizz

The gin fizzis a sour, effervescent cocktail often confused with its sweeter, taller cousin, the Tom Collins. To make a classic gin fizz, combine 2 ounces gin, 1 ounce lemon juice, and 1/2 ounce sugar syrup with ice in a cocktail shaker; shake and strain into an 8-ounce highball glass, topping up with soda water.

The twist: Restaurant 2 Vine has concocted a darker, fruitier fizz perfect for winter sipping. For its Elderberry Fizz, bartenders add concentrated berry syrup to Magellan gin. Sour mix stands in for the lemon and sugar, and the drink is topped off with soda and a lime wedge.

Negroni

When Camillo Negroni asked Gaspare Campari (bar owner and inventor of the aperitif of the same name) to add gin to his favorite mixed drink, the Negroni was born. The Negroni is equal parts gin, sweet vermouth, and Campari, whose ingredients include, among others, quinine, rhubarb, ginseng, and orange peels. The Negroni's more laid-back predecessor is the Americano (Campari, vermouth, and soda water).

Straight up: Tapas 177's Negroni is made to the classic recipe. Puckery and herbal, this is the quintessential aperitif, designed to stimulate the appetite. Like most, this version is garnished with a slice of orange. Purists who want to try this at home can use the original accessory, a burnt orange (directions courtesy of Cocktail Times): holding a 1"x1 1/2" piece of orange peel between thumb and index fingers with skin facing out, hold a lit match over the glass, and with the orange peel about an inch away from the flame, squeeze the peel quickly and firmly. The burst of released oils will ignite, adding a note of orange to the cocktail. Afterward, simply drop the twist in the drink.

Martinis

Like its ingredients, the martini's history is cloaked in mystery. According to most accounts, today's martini evolved from the Martinez. This older cocktail - made from Old Tom gin (a sweeter variety hard to find today), sweet vermouth, maraschino liqueur, and orange bitters - takes its name from Martinez, California, the destination of a commuter who enjoyed the pick-me-up daily.

Over time, the maraschino disappeared, the bitters became optional, and sweet vermouth was traded in for dry. As the memory of Prohibition faded and tipplers began preferring their drinks sweeter, vodka took over for gin, its neutral flavor a better background for syrupy liqueurs and other add-ons. Lovers of gin (known as "Mother's Milk" since the 1820s) retaliated, and to some today a "perfect" martini is a frigid glass of gin with the barest misting of dry vermouth.

The twist: To a purist, none of the following cocktails qualifies as a martini at all - some might be called Kangaroo variations (the Kangaroo = a vodka "martini") - but each is delicious in its own right.

Two89's eponymous signature drink is a juicy splash of pomegranate. The bartender combines Pama Pomegranate liquor and green tea-flavored spirit Zen, topping it off with a splash of cranberry juice. In some of its mixtures the Alexander Street lounge eschews both gin and vodka, basing them instead on specialty liquors: the X-Boyfriend Martini shakes up X-Rated fusion liquor, Stolichnaya vanilla vodka, and pineapple juice; the Hyp-tini takes its name from Hypnotiq, a bottled blend of vodka, tropical fruits, and cognac.

On Park Avenue Café Cibon heralds the changing seasons with luscious mixers like pumpkin and eggnog. For its new Pink Martini, Cibon's bartenders add a Pama pomegranate twist to layers of orange - Grey Goose orange vodka, Gran Marnier, and a dash of orange juice. The Cranberry pairs Skyy vodka with Tomasello's tart wine flavored with the berry.

Lola Bistro and Bar on Monroe Avenue mixes up specialty drinks from the creamy, dessert-in-a-glass Crème Brulee to the puckery, amethyst-hued plum martini. The bar's featured Champagne and Strawberries starts with vodka and strawberry schnapps and finishes with a splash of bubbly and a strawberry garnish.

If you like a classic martini or aren't sure what you prefer, here are some hints:

-There's no "right" gin for Martinis; use a good quality brand you like.

-Chill the glass while you mix the drink.

-Experiment with ratios: try an 8:1 ratio of gin to vermouth, then 4:1 and so on until it tastes right. A dash of orange bitters is optional.

-Don't keep the gin bottle in the freezer! Shake with ice instead; a small amount of the melted ice will properly mellow the drink.