San Francisco in particular, or the Bay Area in General (Oakland, San Jose, etc)?

San Francisco is like Boston in that it's a small-big city. Very walkable. Great transit through BART, Muni and Caltrain. Traffic can be extremely difficult in rush hour (I'd say worse than NYC traffic) and Critical Mass can bring traffic to a screeching halt. If you do drive, learn how to park on hills.

The weather on a given day can vary framatically by location and time of day. I've had days where I had to wear jeans and a sweatshirt in the morning, change to shorts and a tee by noon, and back to jeans by late afternoon.

Golden gate is a great venue for relaxation or exercise, but beware of pan handlers. There's a couple of great bars and night clubs in the Haight-Ashbury area.

Lots of great food in San Fran, Oakland and San Jose. Avoid Chinatown restaurants that *don't* offer chopsticks by default (learned this the hard way).

Fry's is a geek's paradise.

Rush hour communiting via the Bay Bridge is not an option.. don't even think about it.

Hunters Point is nowhere near as bad as white people say it is.

Pac Bell park is a great venue, but it can get chilly there even during the summer.

Lot's of touristy stuff (Golden Gate Bridge, Fisherman's Wharf, Lombard St, Alcatraz) but if you're living there you can go there whenever.

Much, much friendlier than NYC.

If you're very, very lucky you might still find a rent-controlled apartment. But probably not. Otherwise, expect to pay NYC prices for an apartment. I have several friends in the area making very good money at the usual tech companies and none can afford to actually buy a place.

The homeless are the must aggressive I have encountered (and I've spent lots of time in the "bad" areas of most major U.S. cities).

Small city is good. I've heard the vibe there is different than here. Sort of more like a community than a big metropolis. True?

Word on the street I hear is it feels like a small city, from people who move here from NYC anyway. Neighbourhoods are fairly diverse but again probably on a smaller scale than NY. A few famous buildings, hilly areas, street cars, MUNI (bus/subway), SFMOMA again the redheaded stepchild of NY's I hear.. But I love it here.