I will have an extra day in the SF area on the Friday before the faire. I will be staying down just south of the airport. I was thinking about driving up to Muir Woods. Do you think this would be worth it?

I don't have all day - and there are a few things I really want to stop off in SF proper to do. I might do a short walk/easy hike, about a half hour or so, I would probably be more interested in driving around what appears to be the 101 loop. However, it looks like you have to drive through downtown SF just to get there, and then the $7 toll plus the $20 for tollpass for the car. While I have wanted to see redwoods, and like to see the country side, is it really worth it?