Here's the dilemma: Wait for the pedestrian signal that seems never to come - or try to make a break for it through the traffic that sometimes roars, sometimes pokes through the Massachusetts Avenue bottleneck that snakes by Harvard Yard.
Janet Stein, a newly arrived Harvard freshman, chooses the latter. With the adroitness of a combat veteran on maneuvers, she skirts the temporary concrete barriers, hops over the locked bumpers of two cabs, narrowly avoids being sideswiped by a renegade yogurt truck, and arrives, breathless, at the newsstand sitting in the middle of the maze and mess that is Harvard Square.
''Times?'' she inquires.
''New York or London?'' asks the burly cashier.
The Times of London was what his customer wanted. And Harvard Square's legendary Out of Town News Agency gets it, along with a dozen other European dailies, within 24 hours of publication.
That's the sort of amenity one comes to expect here, a fact that seldom fails to impress out-of-towners. Emblazoned on Miss Stein's T-shirt: ''Somehow I don't think we're in Kansas anymore.''
As the somewhat dilapitated front porch of Harvard University, Harvard Square is the meeting ground of choice for many people associated with the 50-odd colleges and universities that call the Boston area home. It is also the premier showcase for the area's street life.
''You can go far with a quarter - or for that matter nothing - in Harvard Square,'' asserts nationally ranked chess master Murray Turnball, who plies his trade - weather permitting - on one of the municipal chess tables on a plaza adjacent to the square. He is the exception to his observation: a game with Murray will cost you a dollar, unless you win or draw. But that, he assures without a trace of modesty, rarely happens, even at the end of a 14-hour day after he's fielded as many as 50 challengers.
Most of the other attractions, however, cost no more than the time one spends to watch them. Twenty feet away, a visiting daredevil from Portugal clad in a leopard-skin bathing suit is juggling flaming torches on a unicycle. In another direction, someone is banging out excerpts from Handel's Royal Fireworks Music on a hammer dulcimer. He can hardly be heard, though. A few paces away, a string trio is belting out Hungarian gypsy rhapsodies. Soon, even they will be overwhelmed. A reggae ensemble is preparing to open shop.
The players have changed, but the throb of activity in Harvard Square is much as it has always been. What is new is that the square is entering the last stages of a $72 million face lift that could radically alter its nature.
Sometime next year the chaotic traffic patterns, narrow sidewalks, and clutter of signs and lampposts that have characterized the square for generations will exist only in the memories of legions of Cambridge residents and students who have endured them. Nearby, on what once was a parking lot and MBTA car yard, a complex including a luxury hotel, expensive condominiums, restaurants and stores is rising. Two other major commercial projects are under construction. More are in the planning stage.
''Every day, every week, every month someone is coming in here with an idea for a development,'' says Cathy Spiegelman, director of the Cambridge Community Development Office. ''If anything, interest is accelerating.''
Such an increase, it is widely felt, will help to expedite Harvard Square's drift down the path that other urban crossroads have traveled: toward expensive stores, boutiques - a trendier, more affluent atmosphere. That, many residents around the square say, is a mixed blessing. Rising demand for retail space is seen as a testimony to the desirability and economic vitality of the square.
''I've got more applicants for space than I have room to accommodate,'' says Robert Friedman, president of the development firm spearheading the largest project in the vicinity. ''Harvard Square is a very desirable place to be. The new space will allow people who've always wanted to locate here to do so.''
Mr. Friedman also believes Harvard Square can easily take the additional office space without becoming glutted. Some stores in the square, he says, have doubled their sales in the last year. And many of the stores in his development, he says, will be of the small, boutique variety that will harmonize with the square's traditional ways. On the other hand, spiraling rents in the area are fanning concerns that, ultimately, few but high-volume, high-profit stores will be able to do business in the area.
Urban planners say that might be a fine prospect for the development of a Quincy Market, where developers are building from a shell, but inappropriate for a tradition-rich area such as Harvard Square. Such an approach might spell the end for many of the quirky little ''mom and pop'' establishments on which the square's character was built.
''The nature of Harvard Square as a commercial entity is being fundamentally changed,'' argues Harvard University architecture Prof. Christopher Chadborne, who earlier this year co-wrote an extensive report on commercial development in the square. ''The 'incubator businesses' - the tailors, the cobblers, and the grocers that served the needs of the community, as well as the enterprises that were really unique to the square - are either being pushed out to the periphery or disappearing altogether.''
The area still has Harvard, though. Many think this will be enough to protect the square from homogenization. The university goes so far as to subsidize rents of some establishments, such as bookstores, that it deems important to its function.
''What makes Harvard Square unique,'' says local book merchant Herb Hillman, ''is the way the community has grown to respond to its needs.'' He cites the 23 bookstores that have sprouted around the square. His own shop, Pangloss, is to bookstores what oatmeal is to breakfast cereal: no-nonsense and good for you. Not to be seen are gimmicky posters trumpeting some coming clearance sale. Just rows of books, usually of the scholarly variety. This is the place to go if you have to get your hands on the two-volume biography of Elihu Root.
Yet despite the following Pangloss has developed among, it and several other stores were displaced from their Harvard Square location onto a side street last year when a building they occupied was torn down to make way for a larger, more profitable structure. Although Mr. Hillman was offered space in the new building , the new rental rate that came with it was too high, he says.
''That could be a real trend,'' worries Gladys Gifford, president of a citizens' watchdog group, the Harvard Square Defense Fund. ''Harvard Square proper is packed, and about the only way to build is up.''
Her organization, along with other citizens' groups, is keeping close tabs on new development proposals as they come in. Harvard Square has few genuinely historic buildings; much of it is cluttered by what experts perhaps charitably call ''background architecture.'' But many want to ensure that the weathered ambiance of the square is not surrendered to encroaching glass and steel.
Along these lines, the Cambridge Development Commission is formulating stricter zoning-regulation proposals that would prevent overdevelopment. Ms. Spiegelman of that office hopes to present the proposals to the Cambridge City Council in midwinter.
Meanwhile, the discernible outlines of the new Harvard Square have taken shape amid the construction rubble that has marked the area for seven years. Only a few weeks ago, the dominant feature in the square had been the five-year-old, 100-foot-wide hole where the MBTA (Masschusetts Bay Transportation Authority) had been digging a new subway extension. Indeed, the long-planned, 3.7-mile lengthening of the Red Line subway from the square out to the Arlington-Cambridge border is the engine for much of the development activity in Harvard Square.
With the covering of that hole, the area has begun sporting broad brick sidewalks lined with 40-foot trees. Antique-type streetlamps are being installed. A small, unfinished amphitheater, nestled next to the future Harvard Square subway stop above what was previously part of Massachusetts Avenue is already a popular nesting spot for the square's counterculture population. Eventually, several pieces of sculpture are expected to adorn the area.
''It won't hurt the street life,'' assures Murray the chess player. In fact, the municipal chess table upon which he's trouncing yet another supplicant would not be there were it not for the construction of Harvard's Holyoke Center - a massive office building abutting the square that has long been the bane of many an urban aesthete.
As long as Harvard Square avoids becoming too steely and shiny, that may always remain so. The stage for the street life is Harvard Square itself. The success of the performing artists there may stem partly from the ease with which they harmonize with the scruffy and shopworn surroundings.
''There's an intelligent grittiness to the place, like the people in it,'' Murray observes. ''That'll never change.''