I'm not sure if you could do much besides find a good place to eat on Wednesday night, but on Sunday there's a bunch to do. Paramount's Great America is pretty close, close enough for you to go there that day (about 10 mins from the airport north along highway 101). For shopping, closest is Valley Fair, if you take 880 south from the airport. Also around that area are a bunch of good restauraunts, if you can tell me where you'll be staying I can bring up a bunch of close-by places.
Going up to SF might not be as viable, but if you guys can do it, there's plenty to see up there. (it's more like an hour, 45 mins gets you to the SF airport)
We'll see you at the regional then!
