I've long been of the opinion that the decline in local socializing (in the physical realm) is due to the advent of air condition, radio, and later television.
Previously people sat on their porches in the evening to escape the heat of the house and thus saw their neighbors nightly. Now we're all in our climate-controlled cocoons.
After moving to this city a few years ago where we had no friends or family, I just started stopping at neighbor houses when I saw them working on something and offered to help. Establishing this pattern of behavior triggered most of them to do the same not only to me but also to other neighbors and now we have a very tight-knit group of people whose only real initial "shared interest" was physical proximity.
When one of the neighbors was diagnosed with terminal cancer, some of the others were wondering what we could do to help. I suggested we ask him what things he wanted done for his house so that he could not worry about such things and focus on his last months with family. So we spent a lot of summer weekends painting, roofing, doing general house repairs. Along with that his teenage boys got to hang around a group of men in a setting where we would naturally banter and tease without any social climbing or the like.
Close to the end of his life my neighbor told several of us that he was happy to know that there were going to be men around his family that would take care of things and serve as role models for his boys. I can't think of anything that would give me more comfort if I was in his position.
So basically, get off your butt in the evenings and walk the neighborhood. Look for someone doing something and offer to help. If nothing else you'll feel good about being able to help someone out and it just may start the chain reaction necessary to build an entirely new social group.