Every Sunday, Jim Haynes -- an American expat in Montparnasse -- holds a party, open to anyone who RSVPs in time. You show up, contribute about 25 euros, have some wine and dinner, and talk to anyone you like. I went last night and met quite a few people -- Americans, Brits, and even Parisiens. I definitely need some pals for my stay here, and this was a great first step.
Jim figures that, over the years, he's had a total of 100,000 people at his parties. He lives in one of a row of artists' studios, with a great little courtyard.