The temperature is expected to rise to the 80's this weekend. To most people, this translates to "Sun!" "Fabulousness!" and "BEACH!"
Here are just a couple of ways to get out in the sun, but without the burden of crazy traffic beach traffic jams.

The Fastest Road to Stinson Beach
Stinson Beach and all its beach-town perks (including Odyssey ice cream, Parkside hamburgers, Sand Dollar's mud pies) is only 20 miles away from San Francisco.
My advice is to avoid Highway 1 and follow these directions instead, especially if you are coming from the East Bay. This route is 3 miles shorter, slightly less trecherous, and therefore traffic moves at a faster pace.
The late afternoon traffic jam out of town can get a bit messy on sunny summer weekends, but it is easy enough to avoid the rush if you decide to stick around town for dinner!
Ferry to Angel Island
Bike, hike, beach - everything you could ever need for a sunny weekend can be found on Angel Island. There is no need to drive either, just go to the ferry building by Pier 39 in San Francisco and hop on. Schedule is available at www.angelislandferry.com/.

Bike or walk across the Golden Gate Bridge
Bike or walk across the Golden Gate Bridge, enjoy the postcard perfect view at the vista point. Just because tourists do it, doesn't mean you won't enjoy it! Once you're there, you can then explore the beautiful beaches of the Marin Headlands.