Do you want it to be a space dedicated to your event, or do you want to simply meet somewhere where the general public is also present?
You could have it at a park or some other outdoor setting. I think it's better to have these things in an environment where other activities are present so that people can form connections based on how they would hang out in their everyday lives. Swingers clubs, and other dedicated venues, often focus on the one narrow aspect of entertainment. Besides, a lot of people, not just polyamorous people, are turned off by what they think of as the "bar" or "club" scene.
You might consider using an art gallery type of space and having a "wine tasting" or something like that. I'm not sure where you are located but if you are near northeastern Massachusetts I have an idea for a place you can use.
Just some things to consider.
Last edited by NeonKaos; 07-18-2010 at 10:30 PM.