NEW YORK (CNN/Money) - The carnival season is upon us and millions of revelers are revving up.

For most Americans, Mardi Gras is synonymous with New Orleans and Carnival means Rio. But a host of towns all over the western world put normal life on hold for a few days leading up to Fat Tuesday, the last day before Lent begins.

The parties have a big economic impact on host cities. Visitors spend lots of money. The gain for New Orleans is calculated as more than $1 billion. Even Mobile, a mid-sized city with a lower Mardi Gras profile, calculates that direct Mardi Gras spending contributes $227 million to the local economy.

People spend for food, drink, and hotel rooms. They also purchase trinkets, beads and other items, buy admissions to view parades, attend dances, and buy costumes.

Throughout Louisiana, towns big and small have a tradition of Mardi Gras.

Shreveport, in the northwestern part of the state, is "about as far as you can get from New Orleans and still be in Louisiana," says Jeff Richard, spokesman for the state tourist office. "But they still have something like 13 krewes that parade for Mardi Gras,"

Other big celebrations take place in Baton Rouge and in Lafayette, the heart of Cajun country.

Then there's the courier (pronounced koo-rear) du Mardi Gras tradition.

In many small Louisiana towns, men head out early on horseback, accompanied by accordion players and fiddlers. They do tricks and stunts – like standing up on the horse's backs – to "entice their fellow citizens to donate chickens, sausage, and other foods, which they take back to the town center where they make a big gumbo and feed everyone," says Richard.

The towns of Eunice and Mamou have particularly good couriers, he says.

Hundreds of carnival celebrations take place throught Latin America.

Rio, thanks, in part, to its peerless setting and the exuberant good spirit of Cariocas (Rio natives), is the most famous. But many carnival aficionados actually prefer the festivities held in two other Brazilian cities, Salvador and Recife, where the rites tend to be more rooted in the African cultural heritage of the residents of those two cities.

Many of the paraders in Rio devote the lion's share of their free time all year round to preparing and planning for their carnival appearence. They organize into huge groups, called samba schools, that choose a theme and build around it with music, dance, decoration, and intricate, colorful costumes.

The participants in Recife and Salvador may not be as excessive, but the celebrations there are no less exciting.

Closer to home and a cheaper flight away is Trinidad, which has a huge, popular carnival that reflects the combination of cultures in the island nation. Other big American carnivals occur in Veracruz and Mazatlan in Mexico.

Back in Old Europe, there are large holiday celebrations in Basel, Cadiz, Nice, and Venice.