Tomorrow morning, three wealthy art-collecting couples – Sherry and Joel Mallin, Zoe and Joel Dictrow, and Ellen and Jerome Stern – will throw open their doors to groups of absolute strangers. The couples, all noted contemporary art buffs, have agreed to allow visitors, in town for the annual Armory Show art fair, to ogle works by such blue-chip artists as Donald Judd, Marlene Dumas, and Chuck Close in their apartments.

These sanctioned snoop sessions are part of the fair organizers’ effort to ensure that the heavy-hitter buyers attend the fair, which opened last night with a benefit for MoMA, and runs until March 14. About 2,500 VIP cards were mailed to deep-pocketed collectors, museum curators and trustees, art advisers, dealers, and other art world honchos – with a daunting 35-page schedule of events, including the apartment tour. It’s enough to make even the most socially ambitious collector shudder.

This year, fair organizers expect around 40,000 visitors to traverse the two giant shipping piers jutting off land on Twelfth Avenue between 50th and 52nd Street. It’s a hassle getting over there, but people fly in from all over the planet to get a peek. Of the 162 international dealers, half came all the way from Europe while a third are from New York.

“I tell people to go to the art fairs,” said dealer Becky Smith of Bellwether gallery, one of the exhibitors. “It’s the Cliff’s Notes of the art world. You can just take it in.”

The fair began in 1994 when four dealers, fed up with a sleepy market, invited their circle of dealers to pay $50 for rooms at the Gramercy Park Hotel. “It was a big hit,” said private dealer Paul Morris, one of the founders. “It was a formula that was in sync.” By 2001, it was mounted on the West Side piers, attracting 11,000 visitors.

The fair’s success has tracked the rocketing contemporary art market. Upper East Side dealers have been racing to open Chelsea outposts, auction prices have left the stratosphere, and Christie’s has even announced a new sales category, “First Open,” for younger artists. The first auction is March 15.

There are many other contemporary-art events this weekend. They include an outdoor mini-fair at Rockefeller Center, organized by two dealers, called Art Rock. Meanwhile, -scope, a fair for newer, younger, and cheaper artists and dealers, comes to the Flatotel Hotel at 152 West 52nd Street. Finally, for a look at the intersection of museums and the market, on March 13 P.S. 1, the contemporary art space affiliated with MoMA, opens “Greater New York,” a show that will anoint a crop of 150 artists.

Last year, artists chosen for the Whitney Biennial flew off stands at the Armory Show. This year, it’s safe to say that inclusion in the P.S. 1 show will attract collectors hunting for tomorrow’s next star, today.

The Armory Show until March 14 (Piers 90 & 92, Twelfth Avenue at 50th & 52nd Streets, 212-645-6440).

-scope from March 11 to March 15 (135 W. 52nd Street, between Sixth and Seventh Avenues, 212-887-9400).