Fares vary among companies. If you are heading to the airport from a hotel, ask about the flat rate, which varies according to destination; otherwise you'll be charged by the mile (which works out to $15 or so from any downtown location). Taxi stands are at shopping centers and hotels; otherwise you must call and reserve a cab. The companies listed don't serve all areas of San Diego County. If you're going somewhere other than downtown, ask if the company serves that area.
Orange Cab (619/223–5555. www.orangecabsandiego.com.)
Silver Cabs (619/280–5555. www.sandiegosilvercab.com.)
Yellow Cab (619/444–4444. www.driveu.com.)