Buses run throughout the city and are an easy way to jump from one neighbourhood to another. A $20 3-Day Passport provides unlimited use of all city-run buses, cable cars and trolleys. They can be purchased at several locations (including the information booth at the airport baggage claim).
Taxis are ubiquitous but can be difficult to hail during events and peak commuter hours. They are the preferred method for quick and easy transportation. Tipping a few dollars above the fare is expected. Save a few taxi switchboards on your cell phone.