Dating Sites/Swinging

There are many websites designed to help connect you to other poly people, or swinging partners if that's your preferred variant:

OKCupid.com - large poly contingent, allows you to be "married" and "available"
Polymatchmaker.com - much smaller community, but explicitly poly
Ashleymadison.com - "married dating", catering to swinging, affairs, and nominally poly
Adultfriendfinder.com - another site geared mostly for swingers and sexual play.
Craigslist - has personals that have been poly tolerant, inconsistant quality of respondents though (portland.craigslist.org)

angelspdx.com - the former "Ace of Hearts" club, now Angel's Sensual Social Club. Members only with poly, swinging, and kink events.
nightshift-nw.com - dance-oriented swingers mingling scene, members only, but no cost for membership. For couples and single women.
club6124.com - an "alternative lifestyle club", geared around swinging and BDSM [unknown if still active]