Ralph Hoagland, who owns the building that once housed the popular movie house, says that competition from USA Cinemas, the chain that has a near-monopoly on Boston-area theaters, prevented the rebuilding of the Orson Welles. "It was hard to get good product," Hoagland says.

Instead, he filled the building with service-oriented shops catering to the new Cambridge consumer. Each of the stores in the former Orson Welles building has at least one other shop in another location around Boston and Cambridge.

But as the new businesses take the place of the old, some small business owners say their establishments can still make a go of it along Mass. Ave., if they adjust to the changing times.

"Once they do a big building, only the big guys can go in," says Susan R. Phelps, co-owner of Hubba Hubba, a store that has been in Cambridge for nine years.

Hubba Hubba, which sells rock music, leather jackets and variety of novelty items, was forced to relocate two years ago in an effort to stay in the area. Now, a high-rise condominium development is being erected in Hubba Hubba's old home. "We moved with an eye to the future," Phelps says.

But while Phelps says small businesses can still survive along Mass. Ave., the new developments--such as the one which edged Hubba Hubba out of its seven-year location--are a "double-edged sword" for most small businesses.

On the one hand, the rents are going up, so it is. harder to find affordable space, she says. But at the same time, business is improving because "the new developments are bringing in people who have more money, people who are better educated," she says. "The alcoholic bums don't give me business."

Bay Square condominiums is the building which edged out Hubba Hubba. The condominiums, which are selling for $150,000 to $400,000 are being advertised in such upscale newspapers and magazines as Harvard Magazine, The Boston Globe and The Tab, Bishop says.

Real estate experts say that the new condominium developments such as Bay Square will definitely have an impact on the neighborhood's composition, but they add that it is not certain whether the condo market is strong enough to make the developments a financial success.

Bishop says, "Sales are taking longer than we had originally anticipated," but adds that she expects sales to pick up this month when customers will be able to see the units. As of late this fall, only 25 percent of the condominiums had been sold, she said.

But the problem is not the location of the new condos, according to one local expert. Rather, it is the state of the real estate market nationwide that is slowing down sales for the new Mass. Ave. units.

"These condominiums are representative of a city-wide pattern," says Joel Alstein, a principal of FARgroup, a Cambridge-based real estate development company. "We are in a glut economy when it comes to condominiums."

"It's not that the area is poor," Alstein says. "Traditionally, a condomiumium in middle Cambridge sells for more than an equivalent unit in East Cambridge or Cambridgeport," Alstein says. The area is very desirable, he says, "because the closer you get to Harvard, the better off you are."

The condominiums--and the stores that have accompanied the developments--were designed with a specific consumer group in mind, Alstein says. The developers have targeted their condos toward "empty nesters"--affluent couples who want to sell their houses in the suburbs after their children have gone off to college.

"But maybe they're not leaving their nests so quickly these days," Alstein says in offering an explanation about the sluggish sales of the new condominiums."