hi there! congrats on your soon to be here baby!
several suggestions, along with the good idea of posting here! not sure where in Seattle you live, so some might not be applicable:
you might consider joining PEPS after the baby comes, you can join a mothers group or a couples group if you wish, these meet weekly with families in your neighborhood, and is a nice way to meet folks with new ones too! www.pepsgroups.org
prenatal yoga is a nice way to meet other pregnant women, and then continue postpartum with the little ones.
many neighborhoods have yahoo group for moms or parents, you might look into joining one or two and posting a similar message, and find like minded mamas. if you tell me where you live, I can let you know if I know of a group,but I bet there will be something!
you also may hook up with some other families if you take a pregnancy class, and you might consider independent classes, which cater to the home birth crowd!
I will let you know if any other ideas come up!