Skip the overpriced bus tours and do it yourself on a $1 Muni fare. Ride the #45 through Chinatown, North Beach, and Union Street's boutiques; walk north three blocks and take the #28 to the Golden Gate Bridge. Or catch the F Line at Fisherman's Wharf and ride the vintage streetcar along the Embarcadero and Market Street to the Castro district, a longtime gay mecca. For a more leisurely excursion, take the #6, #7, or #71 to the fabled Haight-Asbury neighborhood, then up the side (though not to the top) of Twin Peaks.

7 Hostel Maneuvers

Hostelling International's top property, the HI-SF Fisherman's Wharf, boasts what may be the country's most beautiful urban hostel, with views of cypress groves, Alcatraz, and the Golden Gate Bridge (Upper Fort Mason, Building 240, 800/909-4776 or 415/771-1468, from $22.50 for beds in dorms or in family rooms with key). The just-opened HI-SF City Center hostel (685 Ellis St., 800/909-4776 or 415/474-5721; dorm beds from $22, private rooms from $66) makes up for the edgy neighborhood with fancy trimmings-the lobby floor is marble and there's even valet parking (for an additional cost). For a funkier but friendly experience, try Pacific Tradewinds Guest House (680 Sacramento St., 800/486-7975 or 415/433-7970, dorm beds $14 to $24), a private hostel that's laid-back and centrally located.

8 Over Hills, Over Deals

Why pay $15 to $40 for a guided walking tour? City Guides, a program of the San Francisco Public Library, offers dozens of guided tours each week absolutely free (or for a small voluntary donation). Themes run the gamut, from Victoriana to Chinatown to the history of the Golden Gate Bridge. Get schedules at 415/557-4266, www.sfcityguides.org, the Hallidie Plaza Visitors Information Center, or any city library.

9 SF from SFO

Taxis will run $35 to $45, but the cheapest way in from San Francisco airport is Caltrain (650/817/1717); a free shuttle takes you to Millbrae station, from which trains regularly make the 70-minute trip to downtown's San Francisco station for $1.50 ($2 during peak). Or hop the SamTrans BX express bus ($1.10 in exact change; 650/817-1717) to the Colma BART station and ride the BART train (510/465-2278), just under an hour to downtown for another $2.25. Van companies charge $12 to $17 per person. From the Oakland Airport, take them ($27 or more to downtown SF), the AC Transit express bus, route A ($5), or the AirBART shuttle ($2 tickets sold by the machines in terminals 1 and 2; once at the Coliseum station, you'll pay another $2.75 for your BART connection into San Francisco).

10 Ethnic Eats

Ethnic restaurants are mighty easy on the budget. For example, think noodles - a full meal in a bowl under $7: Try the Japannese version at Mifune (1737 Post St., in Japan Center's Kintetsu Building, 415/922-0337), Vietnamese at PPQ (2332 Clement St., 415/386-8266), or pan-Asian at Citrus Club (1790 Haight St., 415/387-6366). The city's best burritos are at El Balazo (1654 Haight St., 415/864-8608), La Canasta (take-out only; 3006 Buchanan St., 415/474-2627), and La Taqueria (iffy neighborhood, bustling restaurant; 2889 Mission St., 415/285-7117). In Italian North Beach, order roast chicken with two sides for under $11 at Gira Polli (659 Union St., 415/434-4472) or Il Pollaio (555 Columbus Ave., 415/362-7727); shovel in four courses - ministrone, salad, pasta of the day, and spumoni - for $10.50 at Capp;s Corner (1600 Powell St., 415/989-2589). Dim sum lunches in Chinatown yield small plates of tasty dumplings for no more than $2.60 a plate at New Asia (722 Pacific Ave., 415/391-6666) and Gold Mountain (644 Broadway, 415/296-7733). On Clement Street's burgeoning Little Asia, between Second and 27th Streets, you'll find block after block of Vietnamese, Chinese, Indian, Thai, Korean, even Burmese - all at rock-bottom prices.

11 Go Soak Yourself

Weekdays before 5 p.m. for just $15, have a luxurious soak and spend all day in the sauna, steam room, and communal baths at Kabuki Springs & Spa (1750 Geary Blvd., 415/922-6000) - and perks like sea salts, chilled cucumber face cloths, and tea are on the house (treatments like massages and facials will cost you, though - $50 and up). Baths are men-only and women-only on alternate days (on coed Tuesdays, swimsuits required); call ahead for the schedule. On evenings and weekends the basic rate goes up to $18.

12 Cultured Pearls