I kind of agree with the "you can drink anytime" dude.
Toronado is a great place no doubt. But there are tons of things to see.
free afternoon and evening: Depends on where you are and what the weather is doing. if it is foggy in the city, check out the Mission District or head east to Oakland (Beer revolution and the Trappist). But if the weather is ok, go check out Alcatraz, it's worth the tour. If the weather is really nice, walk across the golden gate bridge or get out to Ocean Beach and Golden Gate Park. You can walk from the beach to the Haight Ashbury district through the park. Check out the Academy of Sciences or Art Museum if you're into that or just keep walking. From there jump in a cab and go to Toronado and Rosamundo's, the sausage place next store.
The Mission is also cool, except for the hipsters. But good tacos and Zeitgeist is a reasonably cool bar with good beer.
whatever you do, if you have the afternoon and evening, you can definitely do some site seeing and end up at the Toronado or wherever in the evening.