A taxi from Oakland International Airport to downtown Oakland costs about $30, to downtown San Francisco about $45. SuperShuttle (800-258-3826) is one of many door-to-door shuttle services operating out of Oakland International Airport. One-way service to San Francisco destinations costs about $30 for the first person and $8 for the second. East Bay service destinations are also served. Call to reserve.
A cheap, easy transportation option is BART. Air-BART buses run between the airport and the Coliseum BART Station every 10 minutes. Tickets cost $2 and can be purchased from machines at the BART station or in airport terminals. AC Transit Bus 58 also travels between Oakland International Airport and Jack London Sq (stopping at the Coliseum BART Station); the local fare is $1.35.
AC Transit (510-839-2882) has a comprehensive bus network within Oakland. Bus 13 will take you from 14th St downtown to Lake Merritt and Lakeshore Ave. From Broadway downtown, bus 58 goes to Grand Ave; bus 59 runs from Jack London Sq to the Piedmont district; and bus 51 heads to Rockridge and UC Berkeley. Fares are $1.75 and exact change is required.
Weekdays between 11am and 2pm, the Broadway Shuttle provides free transportation along Broadway between the Kaiser Center (Webster and 20th Sts) and Jack London Sq.