I've been to San Francisco around 15 times now I think. It's my favourite place to visit and watch baseball. I usually stay at the Westin on Third Street. Besides taking the BART to and from SFO, I don't use any transit anymore. It's about a 40 minute walk to Little Italy and another 5-10 minutes to walk to Fisherman's Wharf. The ball park is 20 minutes the other way. I've also stayed at Hilton on O'Farrell, Parc 55, Grand Hyatt, The Orchard and The Pickwick. The city is very safe. I've never once felt like I was in any kind of danger.
I know there are threads about this. I think there is a restaurant one and a travel one. I've posted numerous times in each one.
Here's a past link asking almost the same question, including calling it San Fran.
http://forum.calgarypuck.com/archive.../t-108364.html