I live on <800 a month in Pittsburgh, soon to be <700. It's actually becoming a pretty big tech city, all the major companies (Microsoft, Google, etc) have stuff going on here, and there's a lot of opportunities to make connections to help with whatever project you've got going. It's right near some great parks, and the city itself is packed with trees and grass...
It is cold in the winter, but it's also hot in the spring/summer.
It is post industrial in the sense that the economy has moved on from industrial type stuff like steel manufacturing -- the economy is very tech/service oriented, with lots of computer/tech/robotics startups and so on, as well as a large health care sector (University of Pittsburgh Medical Center runs their own health insurance which covers a significant portion of the entire state of PA). It was one of the cities least hit by the housing crisis and the economic backlash from that.
As for dangerous -- there are some bad areas, like in every city, but for the most part it's very safe. Safer than any big city in CA for sure.
I'm moving from SF to Pittsburgh in about a month. What's the best way to get info on local meetups/resources/etc? I'm hoping to meet up with some like minded people and maybe even find a co-founder when I move out there.