I don't think it has hindered us all that much. Before there were cell phones, email, twitter, and Facebook people were generally in contact for the most part with people that lived in their own town, co-workers, and friends/family in (their) area.
I believe the same face to face people in most people's lives hasn't changed. People still get together for parties, bbqs, movies, shopping, double dates, beach and park outings. Nightclubs, sports bars, concert arenas,amusement parks, and resturants are filled with friends or families. Not many cities resemble a ghost town. People still meet in person.
Higher gas prices and heavy traffic congestion may have a bigger effect on some people regarding making crosstown trips. Age is another factor. The older one becomes the less incline they are to want to deal with crowds. Most people however don't choose to imprison themselves in their home. :-)
On the upside of things cell phones, email, twitter, Facebook, and Skype have made it much more affordable to maintain contact with those who are a long distance from us on a regular basis. Before these inventions people who lived far apart made the occassional expensive long-distance call or they mailed a letter/post card from time to time. Today the average person is in contact with (more) people than ever on a (regular) basis regardless of their distance!