Cheap Chick Bargain Bulletin-Open House New York (October 4-5, 2008)!

Open House New York is like the Holy Grail of cheapness, at least in the New York City area. It's a once-a-year happening (info here: http://www.ohny.org/) held in the fall, where the doors of interesting and unusual architectural and historic spaces are literally open to the public for FREE all weekend. Spaces include houses of worship, office buildings, restaurants, bakeries, gardens, stores, theaters, hotels, galleries, museums and historic sites, and even cemetaries. Previously I've visited the Chrysler Building, Temple Emanu-El, Roosevelt Island, Gracie Mansion, the Rockefeller Center Gardens, and the Teddy Roosevelt birthplace (yup, in case you didn't know he was born right here in New York City.) Talks and tours aren't the only highlight of the weekend; there are trolley rides, glass blowing demonstrations, and even theatrical and dance-related performances. This is a chance for city-dwellers to discover hidden New York and save a buck or two while doing it-many of the venues regularly charge admission and tour fees.
Location info: All over NYC!