In the ever-changing world of frozen dairy desserts, fame is a transient thing. Every confection has a brief shot at glory, a moment in the sun, and then it melts away.

As Jane Fonda struts lycra-clad through home entertainment centers and the word "creamy" becomes an insult, 10 percent butterfat ice cream has joined Spam in the gastronomic archives. But for the true purist, even frozen yogurt tastes too rich.

For those people, who wage daily battles against Peruvian Grease Platters in the dining hall and rotating scale dials in the bathroom, there is a new ice cream substitute.

Since early fall, Alethea W. Black '91 and Kristina W. Friberg '91 have sold Tasti D-Lite out of the Cafe Paradiso on Brattle St. Already they have a following.

The two roommates and business partners say they started the business because they loved the product.

During their first year, Friberg explains,"Alethea and I were both frequent customers ofLuscious Licks, to say the least. Then Aletheaspent the summer working in New York anddiscovered Tasti D-Lite, which has half thecalories of frozen yogurt and she liked it a lotbetter."

Black explained that while she was interning atChase Manhattan after her first year she routinelyvisited a Tasti D-Lite store during lunch time."I'd spend the first half hour waiting in line andthen the second enjoying it," she says, smilinglike the proverbial cat.

Guilt-free, and yummy too, according to Greg B.Felker, a John F. Kennedy School of Governmentstaff member and Tasti devotee. "Let me stateunequivocally that my interest in Tasti D-Lite isthe taste," he says. "I'm not concerned withcalories."

The co-owners work 50 hours a week each, saysFriberg, standing behind blue counters anddispensing the swirled frozen dessert to thecustomers she affectionately calls her "regulars."

Last year, they got the distributorship,planned the business and looked for a location."We didn't want our own store because that wouldbe too large and too much of a deal," says Black.

In their corner of Cafe Paradisio, 12 neatlycovered bins of toppings line the counter top, andcandy-colored bottles of flavoring stand along thewindow-sill. Burnt-orange Egg Nog clashes slightlywith luminescent yellow Banana, translucent greenPistachio and red Apple Pie.

They have 44 raw flavors, Friberg says, andlists 83 when including the possible blends. But,she mutters quietly, with the glint to the appliedmath concentrator in her eye, "There is thepossibility of 44 choose 2."

"What?" asks Black.

"Just bringing in my statistics," says Friberg.

Black and Friberg are never satisfied withmaintaining the status quo in their Tasti D-Litestand. They are constantly makingimprovements--ordering new toppings, buying largersigns, even making t-shirts.