Walking is always free in New York, and with its buildings and signs and people and unexpected oddities, densely packed Manhattan is an especially great place to walk--except on the coldest days, which tend to be after the holidays. The holiday season adds an extra level of charm to New York in certain parts of town--and it's free for anyone willing to put one foot in front of the other.
Fifth Avenue and its nearby streets have a special concentration of holiday decor ideal for a slow stroll, particularly the shop windows of major department stores. Macy's Herald Square puts on "Santaland," Saks Fifth Avenue decorates its windows in the holiday spirit, and Lord & Taylor also puts on a show.
Also, take a wall through Central Park and attend some of the holiday events there. Many of them are free, but check in advance for their exact schedule since they vary from year to year. Take the kids to Belvedere Castle, mid-park at 79th, for a visit Santa, or see the annual lighting of the Charles A. Dana Discovery Center at 110th between Lenox and Fifth avenues.
The ceremonial first lighting of the the famed Rockefeller Center Christmas tree is in late November or early December, and the event is free--and crowded. If attending the ceremony itself isn't your thing, go see the lighted tree later in the season. It's always spectacular and free.
In early December, visitors can enjoy the annual Winter's Eve, a festival featuring activities for kids and grown-ups, and including street entertainment such as musicians, jugglers, stiltwalkers and more. Columbus Circle and nearby streets are the site for this free event.
If you don't mind the crowds and the noise and the excitement, Times Square on New Year's Eve doesn't cost anything, but you do have to come early to stake out a spot and be prepared to stay there. Crowd control measures mean that if you leave your spot, you can't come back--so seeing the Big Ball drop will be an investment in time rather than money.
A surprising number of events are free and open to the public all year in New York. There are free musical performances, readings by authors, kids' events, art galleries and even free theater performances and movies. A little digging reveals a whole zero-cost world of excellent entertainment and culture beyond the big-ticket items like Broadway shows and pop-star performances.
Some museums in New York are free all the time, including the American Numismatic Society, the Museum at the Fashion Institute of Technology, the Museum of American Folk Art and the National Museum of the American Indian. Others--such as the world-renowned American Museum of Natural History, the Metropolitan Museum of Art and the Brooklyn Museum of Art--have "suggested contribution" policies. If you're really hard up, you don't have to contribute to get in, even though small contributions help support the museums in a big way. Still other museums have free days or hours. These change, so it's best to check before you go.
It's also possible to join a free tour of notable places in New York. The New York Public Library's main branch in Midtown gives daily free tours of its beautiful building. The Federal Reserve Bank of New York, which is downtown, likewise offers free tours. There's even a free brewery tour in Manhattan's only working brewery, Chelsea Brewing Company, 19th Street at the Hudson River.