There are many thousands of web cams around the world, but none offers quite this nice of a view. At WebMarin.com you will find a live view of the bay (when not foggy or dark) that will remind you of why you are riding the ferry to work instead of sitting in a car on a crowded highway.
The web site is run by Don Strickler and the photos are updated once every minute.
Here is a sample photo grabbed just now to show it is real. Click on the photo for a larger image and then drop by Don’s site to see a real-time image of the San Francisco bay.