When I'm in San Francisco, I'm not sure I've EVER seen a reptile store. One really COOL place to go is the Bone Room. They sell fossils and all sorts of awesomeness. Really worth going to. Those are sea lions, and they SMELL, but it's rather neat to see them if you aren't used to seeing sea lions where you live.
There's Castro street for flair, and many many fetish shops, loads of great resturants, and a ghost/vampire type tour you can take after dark(which I missed out on, since i was too busy with the main reason I went, so I didn't get to go).
Make sure you wear comfy shoes, and plan on walking half as much as you would normally, because EVERYPLACE in San Francisco is UPHILL.
Oh!! You have to hit the Wharf, since that's Ghiradelli's and the original SourDough Bread company too! Everything is higher in price, and hard to get to, traffic is insane and there is hordes of people everywhere. In San Francisco, they don't seem to have speed limits in the city, instead they have pedestrians. You can't drive two blocks without one or fifty running into the road in front of your vehicle. It's like really tall lemmings.
I'm sure you'll have a lot of fun! If you find any reptile places to go to, I want info! I'll be going back in October.