I will be in San Francisco on a business trip in Mid-October. At the end of the trip I will have one full day to myself and wanted to know what you guys think I should do on that one day without exhausting myself. 
It will be a Friday so I’d also appreciate suggestions as to whether there is a nice Masjid in the City Centre where I could go for Jummah.
Re: Things to do in San Francisco (in one day)
Btw, my hotel is at Fisherman's Wharf (if that's of any help).
Fisherman’s Wharf (Pier 39) area is a tourist attraction itself and you can spend few hours there. You can take a ferry to Alcatraz right from there. You should also take a trip to Union Square on cable car.
Beside that Golden Gate Bridge, Crooked Street (Lombard Street) and Twin Peaks are most common tourist attractions of San Francisco City.
Following are the recommended eateries:
Naan n Curry
Chutney Restaurant | Indian & Pakistani Restaurant in the Bay Area & San Francisco
For Jumma prayers, you can go to Masjid Noor Al-Islam, 48 Golden Gate Avenue,
San Francisco, CA 94102, phone 415-292-9709, Alsabeel Masjid Noor Al-Islam - Mosque Managed by Sheikh Safwat Morsy - June-06-09
Let me know if you need any other specific information.
Re: Things to do in San Francisco (in one day)
I just went to San Fran last weekend for the first time. Was there for 3 days and went to fishermans wharf twice, union square twice, and Westfield Center which is a mall. Didnt go to golden gate cuz theres nothing great about a bridge.
Definitely suggest you check out fishermans wharf theres just too much junk food to eat there. If you're into it, go to alcatrez, theyve converted the prison into a museum, ive heard its great but didnt care much for it. dont miss union square if u wanna shop.
the weather there has gotten really cold. i was there for three days, first day it was nice and warm, then it got really cold, really fast and i ended up catching a cold.
dress warmly and have fun!
Re: Things to do in San Francisco (in one day)
Thanks to both of you. Looking forward to my trip.