Philadelphia Arthur Ross Gallery of the University of Pennsylvania— Always free (215/898-2083). Philadelphia Museum of Art — Free on Sunday until 1 p.m. (215/763-8100). University of Pennsylvania Museum of Archaeology & Anthropology— Free on Sunday (215/898-4001).
San Francisco California Academy of Sciences, including the Natural History Museum, the Morrison Planetarium and the Steinhart Aquarium— Free the first Wednesday of each month (415/750-7016). Cartoon Art Museum— Pay what you wish the first Wednesday of each month (415/227-8666). Exploratorium— Free the first Wednesday of each month (415/561-0360). San Francisco Cable Car Museum— Always free (415/474-1887). San Francisco Maritime National Historical Park— Always free (415/556-3002). San Francisco Zoo— Free the first Wednesday of each month (415/753-7083). Wells Fargo History Museum— Always free (415/396-2619).
Seattle Frye Art Museum— Always free (206/622-9250). Seattle Art Museum— Free the first Thursday of each month (206/654-3100).
Washington, D.C. All divisions of the Smithsonian are free, including the National Air & Space Museum and the National Portrait Gallery (202/357-2700).
When to go where: a month-by-month guide to bargains across the country
January RAILWAY Post-holidays, a train trip is just the ticket. Amtrak's 30-day, $450 North America Rail Pass (800/872-7245) allows unlimited stops at more than 900 U.S. and Canadian destinations.
February SALT LAKE CITY Feel the need for speed?Take a ride on the ice rocket, a small bobsled, or try out ski jumping with the Utah Winter Sports Park Pass, $25 if you buy Southwest Airlines' Utah Ski Vacation package (800/423-5683). The price, from $215 per person, includes hotel, lift tickets at a choice of five ski resort areas near Salt Lake City, and airfare from Boise (prices are higher from other cities).
March COLORADO Can't decide whether to hit the slopes or the spa?You might find the answer during Colorado's shoulder season. In Telluride, many of the hotels drop their rates, including the Peaks Resort & Spa (800/789-2220 or 970/728-6800). It costs just $225 a night, double, March 29 through April 12— and the resort kicks in two lift tickets a day.
April HAWAII When winter traffic subsides, there are good deals to be had on the islands. One of the best, United Vacations' $778 Maui Plus package (800/ 328-6877), is available April 1 through December 8 and gives you a hotel room for five nights and a rental car.
May NANTUCKET To celebrate the calm before the summer rush, four inns— Roberts House, Manor House, Meeting House, Periwinkle Guest House— are offering a getaway package starting at $245, double. You get two nights' midweek accommodations and some meals (800/837-2914 or 508/228-0600).
June ALASKA When the weather in America's northernmost state isn't pleasant, it's forbidding, so it's hard to escape peak rates. An economical way to cover a lot of ground is with the $499 AlaskaPass (800/248-7598), which allows eight days of unlimited travel on the Alaska Railroad, the Alaska Marine Highway ferry line, and BC Ferries. (Longer passes are also available.)
July NATIONAL PARKS How to beat midsummer's high prices?Take Trek America's 17-day National Parks of the West van tour (800/221-0596), which wends through Yellowstone, Grand Teton, Grand Canyon, and Arches national parks. On the agenda: hiking, white-water rafting, horseback riding, mountain biking. The July 11 departure costs $950 a person, with hotels and activities (food is extra).
August ARIZONA Remember: it's a dry heat. The Lodge at Ventana Canyon (800/828-5701), a 49-suite resort in Tucson, offers three nights for just $800, double. Guests also receive points to trade toward trail rides, Sonoran Desert Jeep tours, and helicopter excursions.
September CRUISES Each fall and spring, cruise lines reposition their fleets from one seasonal destination to another. Passengers who go along for the ride can get exceptional deals. In September, when Princess (800/421-1700) moves ships from Alaska to the Caribbean, a three-day Vancouver-- to-- Los Angeles jaunt can be had for as little as $329 a person. (This May, the reverse trip is $325.)
October PUERTO RICO For those willing to chance it, hurricane season in the Caribbean means empty beaches, low rates, and— between storms— splendid, sunny weather. The $150-per-night Four-for-Free package at El Conquistador Resort & Country Club (800/468-5228) includes a room upgrade, a fifth night free, a daily program of activities for children, and meals for kids under 12.
November NORTHERN CALIFORNIA Fall is a cool time of year in redwood country, perfect for tennis. The three-day, $777 Tennis Getaway package at the Carmel Valley Ranch (800/422-7635) buys you a one-bedroom suite, an hour-long tennis clinic, and unlimited court time.
December FLORIDA While parts of the state (Orlando, the Keys) enjoy high season year-round, early December brings the shade of low season to the Gulf Coast. South Seas Plantation Resort & Yacht Harbour on Captiva Island (800/227-8482) offers a three-night package for $570 through December 17. It includes two daily activities (tennis, kayaking, canoeing, fishing) per person.