The sea lions hang out by pier 39. Sometimes you get lots like this picture or sometimes you only get a couple rafts full, although lately they're always full. Its generally hard to out-stink a place where fisherman frequent, but the sea lions manage to do it with style. If you have visions of yourself swimming with them like dolphins, forget it, they have known to attack swimmers. Its worth a visit if you're doing the touristy thing, and if you get bit, you'll have a scar to show off to your buddies. John's Blog has more on the area.