Actor Robert De Niro used to be just another famous guest in the world of swanky hotels.

Now, he’s opening his own posh lodge in downtown Manhattan.

Standing seven stories high at the corner of Greenwich and North Moore streets, Mr. De Niro’s roughly 75,000-square-foot Greenwich Hotel, which is scheduled to open this spring, will include all the world-class amenities that one might expect from a wealthy, two-time Oscar winner: Moroccan tiles, Tibetan rugs, French doors, Siberian oak floors—even a fancy Tuscan-style restaurant and chichi Shibui Spa.

Room rates will be just as extravagant, starting at $725 per night.

And people will probably pay it—if not for the stylish surroundings or celebrity cachet, then perhaps because every other decent place in town is either entirely booked or equally expensive.

Given the rising demand for lodgings, with tourism rebounding to record levels over the past few years, the annual average room rate in Manhattan has escalated more than 50 percent since 2003 to nearly $300 a night, according to the city’s latest figures.

Mr. De Niro isn’t the only A-list luminary looking to get in on the lucrative action.

Hip-hop mogul Shawn Carter, a.k.a. Jay-Z, perhaps foreshadowed his own foray into the business when he first unleashed the celebratory rap lyric “after the show it’s the after party and after the party is the hotel lobby.”

The Grammy-winning former president of Def Jam records and part-time party promoter announced this past December that he, too, is planning to build a new high-end hotel in Manhattan with the help of CB Developers.

The reported $66.4 million, 150,000-square-foot project, located on the site of an old warehouse and parking garage on West 22nd Street, will serve as the flagship for a whole new chain of luxury lodgings called J Hotels. “Everything is in a very developmental stage,” noted Mr. Carter’s publicist, who declined further comment.

Fashion designer Giorgio Armani, meanwhile, is searching for a chic spot to create a New York counterpart in the next few years to his opulent Armani Hotel & Residences in Dubai.

For Mr. Armani, who announced plans in 2005 to open at least seven luxury hotels within 10 years, it seemed only in keeping with a grander vision of his eponymous apparel label becoming a complete lifestyle brand.

As the designer previously explained in a statement, “Today, more than ever before fashion has expanded to encompass our way of life, not just how we dress, but where we live, which restaurants we eat at, where we holiday and which hotels we stay in.”

Indeed, the hotel business, in particular, has become increasingly fashionable over the years.

Even the proprietors of many old, run-down Manhattan hostelries, including the Malibu on the Upper West Side and the Portland Square Hotel near Times Square, have lately undertaken major renovations and rebranding campaigns to keep up with the trendy boutique-hotel movement, which continues to raise the expectation level in terms of design and functionality far above the bare necessities of budget accommodations and standardized aesthetics of national chains.

Widely credited for pioneering the boutique model, hospitality guru Ian Schrager may be just as responsible for paving the way for the new celebrity hoteliers.

As part owner of notorious nightclub Studio 54, Mr. Schrager was already somewhat famous by the time he entered the hotel business in 1984. But after opening Manhattan’s highly stylized Royalton Hotel, with its famous lobby designed by Philippe Starck, in addition to the Paramount and the Hudson hotels, among others, Mr. Schrager transcended the usually ephemeral influence of a mere liquor-industry impresario, becoming a bona fide tastemaker and trendsettter.

His iconic rock star persona set the standard for the next wave of hip hotel operators, including jet-setters André Balazs and Jason Pomeranc, each of whom run chic hotels both in Los Angeles and New York. And each has made a name for himself on the social circuit, although neither was very famous to begin with.

It remains a very sexy profession, if only in appearance. “I could dispel that idea pretty quickly if anyone follows me around for a day,” said Mr. Pomeranc, 36, who just returned to New York after opening a new hotel in Beverly Hills last week. “The energy of the night, opening the hotel to all of Hollywood and L.A., it was a really satisfying moment,” he said. “But that doesn’t mean it wasn’t two years of struggle to get to that moment, and every day it will involve a little more struggle to keep that going.”

Mr. Pomeranc’s company, Thompson Hotels, is also planning to open a number of new hotels in New York this spring, including one near Wall Street and another on the Lower East Side. About a year from now, Mr. Pomeranc said he also hopes to open a third hotel in Tribeca—where he will face off in direct competition with Mr. De Niro’s Greenwich Hotel.

“If that project helps establish Tribeca as an end destination for hotels at high rates, that only benefits me,” said Mr. Pomeranc, who was none too surprised by the big-name celebrities now encroaching on his turf. “When people have achieved a tremendous level of success in a creative field, they have this desire to transfer that creativity into another field of expression—I think that’s the attraction,” he said. “I don’t think they want to use it as another vehicle of fame because they’ve already achieved that.”

Such superstars have long turned to the hospitality sector when seeking to invest their talents and riches in some sort of side project. For a while, it seemed as if every single one of them was opening a restaurant or nightclub in New York.

Just last summer, singer Justin Timberlake and friends brought Memphis-style barbecue to Manhattan with the splashy opening of Southern Hospitality on the Upper East Side. Years earlier, his former girlfriend, pop star Britney Spears, tried to cook up a similar Southern style as part-owner of the ill-fated eatery NYLA.

Actor Stephen Baldwin launched Alaia and later Luahn in Union Square, and Sex and the City star Chris Noth was the real-life Mr. Big behind the Cutting Room on West 24th Street.

Some of these star-studded ventures proved spectacular business failures on a par with their celebrity proprietors’ own career-worst performances. Consider actor Sylvester Stallone’s widely panned 1995 box office flop Judge Dredd versus the twice-bankrupted Planet Hollywood franchise, which he helped launch alongside Bruce Willis and Arnold Schwarzenegger in Times Square back in 1991.

Yet other celeb-tied enterprises rode the fame train to critical acclaim, further bolstering their public persona, as well as their financial portfolio.

Mr. De Niro himself has partnered with a number of other famous investors, including Sean Penn, Russell Simmons and Bob and Harvey Weinstein, in the operation of Tribeca Grill, which opened in 1990; it’s an endeavor credited for elevating the profile of the entire neighborhood.

Mr. De Niro’s subsequent partnership with Chef Nobu Matsuhisa in launching the perennially popular Asian fusion restaurant Nobu on Hudson Street in 1994 not only further enhanced that emerging neighborhood vibe but also spawned 16 additional Nobu locations, including two others in New York.

Mr. Carter similarly parlayed the success of his sports-themed 40/40 club in West Chelsea into additional locations in Las Vegas and Atlantic City.

For guys like them, hotels are the new restaurants, the eventual next step in celebrity entrepreneurship.

“I think it’s all good—each one of them has a distinctive personality and they can make their property reflect that personality,” said George Fertitta, CEO of the city’s tourism office, NYC & Company, who seems delighted by the additional marketing opportunities presented by new celebrity-run hotels. “It’s just another way that we can talk about all that New York has to offer,” he said.

It’s Mr. Fertitta’s job to be optimistic about all the hotel construction going on. After all, he’s in charge of Mayor Bloomberg’s plan to attract 50 million travelers annually to New York City by 2015. Hotel development plays a crucial role, of course, as high demand for rooms is squeezing the current supply, despite some 1,000 new hotel units getting built over the past year.

City projections point to a total of 13,000 new hotel rooms by 2010, with builders both famous and not. But not everyone buys into the big numbers.

“With a lot of these announced projects, I don’t necessarily think all of them are going to happen,” said Mr. Pomeranc. “The banking industry will weed out some projects. There still is a demand for more rooms. But this business is a combination of real-estate development, operations, service—it’s very complicated. And the snapshot in time like we have right now is not necessarily indicative of what the industry’s going to be for the next 10 years.

“It’s very important,” he added, “whether you’re a designer, a musician or an actor, that ultimately your partners and your operations team are experienced in the industry for a long time, because the longevity of these projects is going to hinge on true hotel-related aspects, not the association with the famous name.”