21st Amendment
See above under Eat.
District
Old furniture store converted to the latest wine-bar in SoMa.
Gordon Biersch Brewery
See above under Eat.
Jillians
This upscale sports bar has a huge video wall great for watching sports. There are also 8 well kept pool tables for something to do. This bar becomes a dance club on Friday and Saturday nights with a strict dress code -- nice shoes required.
Thirsty Bear Brewing Company
An upscale brewpub/restaurant and favorite expense-account spot for the trade show crowd from nearby Moscone Center. The cask-conditioned ale is satisfying, but the place can get crowded.
Tres Agaves
See above under Eat.
City Beer Store & Tasting Bar
Your best bet for beer to go.
Clubs
1015
Lines all night outside during the weekend. A twenty-something meat market.
The Cat Club
Thursday is 80's night where you're guaranteed to hear at least one Madonna song throughout the night.
DNA Lounge
The DNA Lounge is a 2-story club which often caters to the geekier "digerati" crowd. One of the founders is Jamie Zawinski, a former Netscape superstar and Internet nabob. Events feature themed electronica dance nights Industrial, Techno, Trance, etc and live bands.
The End Up
An SF institution. Essentially doesn't close on the weekend, and thus where people 'end up'. Great old school SF house music. Unexpected outdoor patio/waterfall space to chill.
Mezzanine
Where all the shirtless buff gay boys go. Great sound system. If you like cheesy techno and disco diva wailing music, this is the place.
The Stud
Fun semi-dingy club. Don't miss Trannyshack, Tuesdays at midnight. Very worth the sleep deprivation at work the next day.
Many of San Francisco's best dance clubs are in SoMa.