For years, my third place was Stone Mountain Airport. When the Summer Olympics came through and closed the airport, we moved the EAA hanger to Lawrenceville (LZU) and we hung out there for quite a while. After I started to stay home with my children, my third place was indeed church - and it was a real shift for me - I entered into an identity crisis of sorts. But that's a story for another time.
When I went to seminary, the seminary fulfilled the third place needs - however as an older student and one that commuted in, it was not complete. I started to blog and use chatrooms. That's where my true third place came in. I frequented Real Live Preacher's chatroom and community formed. That was good for a while - maybe two years. Then the community dissolved and I began to use Second Life, where another group of people coalesced into community. However, my participation in this medium was disruptive to my family and I became discouraged in finding funding for a UM mission and I began to drift into Facebook.
Facebook, Twitter and other social mediums are now my third place. I do yearn for more face to face interaction. It's not perfect.