That one seems like a no-brainer, but, seriously, have you ever considered the many charities to which you could give your time? Your local civic association is always in need of volunteers for projects like "let's clean up the park before a hundred dogs crap on it again" and Toys-for-Tots, Christmas in April, and so on. Don't forget about all your local politicians who need help with their campaigns. If one impresses you, offer to knock on a few doors for her or him. Host a cheese and cracker party for the community to get to know the candidate.
These are not only friend-making possibilities, they are networking opportunities and a chance to give back and feel good about that. Remember that "Seinfeld" episode where Jerry gets a girl's number off of an AIDS walk? Bingo. That's what I'm talking about.