BOSTON (TheStreet) -- Winter weather is cranking up just as the holiday season winds down, making now the best time to plan a January vacation.

"I always think that January a great time to get away because it's really the beginning of when I start to tire of cold weather,"

TripAdvisor.com

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travel expert Josey Miller says. "I'm in the holiday spirit in December and enjoying the chill -- but by January, I'm starting to think: 'OK, when is spring coming?" "

Super-powdery snow at the Blue Sky Basin in Vail, Colo.

Miller adds that January is a "shoulder season" at some resort destinations, offering lower prices than you'd find either around Christmas or in February when many schools have vacation weeks.

In fact, the only major downside to taking a January vacation is having to choose between a warm tropical beach and a cozy ski resort.

"There's no real right answer," Miller says. "It all depends on your personal preference."

Here are four of Miller's favorite destinations for posh January getaways:

Bora Bora, French Polynesia

This island 4,100 miles southwest of Los Angeles in the South Pacific near Tahiti attracts lots of winter tourists with its white-sand beaches, turquoise waters and scuba and snorkeling spots packed with tropical fish.

"As you fly in, your jaw just drops at the view of this beautiful island," says Miller, who went there for her honeymoon in 2007.

Centered around Mount Otemanu, Bora Bora features resorts with rooms built on stilts right over the water.

Miller recommends a "motu picnic" -- a private feast of local foods that tour operators will serve you in a beach chair set in shallow waters off a motu, or small islet.

She also touts the local snorkeling and scuba diving, where you can swim with rays, reef sharks and Napoleon wrasse, huge tropical fish that look like something out of a cartoon.

"I love the scuba diving, but honestly, you don't have to rush around and feel busy on Bora Bora," Miller says. "You can just find a spot with a view of Mount Otemanu and get lost in the beauty of the place."

The Four Seasons Bora Bora

is the five-star hotel the gets the highest user ratings on TripAdvisor.com. Rooms are $884 to $2,448 a night.

Lizard Island, Australia

The 40 suites of Australia's Lizard Island resort are the only accommodations at Lizard Island National Park, a tropical paradise some 16 miles offshore.

Located off Australia's Great Barrier Reef, Lizard Island's 24 sugar-sand beaches offer blue water, coral reefs and some of the world's best snorkeling, sport fishing and scuba diving.

"Lizard Island is all about sunbathing, spa-ing and sunset admiring," Miller says.

She especially likes scuba diving at Cod Hole, which is supposed to have potato cod that are as big as cars. Miller didn't see that on her trip to the island, but did encounter giant sea clams while snorkeling that are "so big they're shocking. They don't seem real."

Travel + Leisure magazine named the

Lizard Island resort

as the best hotel in the Australia/New Zealand/South Pacific area for 2008. Suites at the five-star hotel cost $1,402 to $1,752 a night.

St. Moritz, Switzerland

This Alpine playground boasts such good skiing and other cold-weather sports that it's one of just three locations across the globe that have hosted the Winter Olympics twice.

"Skiing is really what you go to St. Moritz for," Miller says.

St. Moritz's famous Corviglia Mountain, site of the 2003 FIS Alpine World Ski Championship, boasts the steepest start slope in all of Switzerland -- the Piz Nair Wall. This slope's sharp vertical drop allows skiers to accelerate from 0 to 100 kph in just 7 seconds.

St. Moritz also offers world-class bobsledding, tobogganing, cross-country skiing and winter hiking -- all with picture-perfect mountain and lake views.

If you're not the outdoorsy type, the town also hosts dozens of chic spas, shops, restaurants, casinos and nightclubs.

However, all of that wintertime fun doesn't come cheap.

TripAdvisor's annual TripIndex Ski rankings list St. Moritz as Europe's priciest major ski resort. One day's hotel stay, ski rental, lift ticket, a meal and a beer will set you back about $529 on average.

Badrutt's Palace Hotel

gets the highest marks from TripAdvisor among five-star accommodations. Rooms cost $306 to $3,546 a night.

Vail, Colo.

"When it comes to Vail, there's one word you hear most often: 'powder,' " Miller says.

Located about 100 miles west of Denver, Vail Mountain's powdery snow and 193 trails have long made it a top January destination for America's rich and famous skiers.

The area also offers a wide variety of other winter activities, from snow tubing (riding an inner tube down the mountain) to "snowcatting" -- touring the area from the comfort of a snowplow-like vehicle called a snowcat.

For those who prefer the great indoors, Vail also has lots of upscale shops, restaurants and nightclubs.

But, like St. Moritz, Vail tops TripAdvisor's TripIndex Ski rankings in terms of costliness. One day's hotel stay, ski rental, lift ticket and one meal and a beer there average $745.56 -- the highest price among 20 major North American ski resorts surveyed.

Stay at the

Four Seasons Resort Vail

, TripAdvisor's top-rated five-star hotel, and you can expect to spend even more. Rooms are $420 to $1,553 a night.