When I go to the city I dont usually go to meet women, I go to dance. But if you're looking to meet women at clubs while in SF the two most well known are 1015 folsom (ten 15) which is located at 1015 Folsom st. heheh
The other is Ruby Skyes.
If you're looking to dance I recommend 1015. If you wanna meet woman, go to Ruby Skyes. Both have a bar and both are 21+. Both are $20 cover.
The line at 1015 goes pretty quick, RS takes longer.
If you're looking for a good gay spot, go to The Cafe or to Liquids.
hahah.
Oh, and you may want to bring some earplugs. The systems are louder than the norm at times. Being that I go pretty often, I bring earplugs and a hand towel. But that's cause I dance all night.
Anyway, hope you have fun! I'll be up in Chico so no parties in the city for me. Just a bunch of drunk college girls! But that ain't too shabby, hahah.
*Edit* of you're looking for something a little more classy but still stylish, try the DNA Lounge.
You can also try Club Ibiza across the water in Oakland. It's a hotel and Club. It used to be a swingers hotel. Yeah, the sucky sucky kind of swingers. Now it's a club.
Go here to find details on clubs and schtuff:
http://SFgate.com/
-Shadow