There is a great new web series on polyamory! Not a documentary, it's a drama. Each episode is only 5-6 minutes so it doesn't take a lot of time but it's funny and poignant. It's meaningful for all types of relationships and has some local interest, such as mentions of Microsoft employees. Watch it on YouTube!
FAMILY - a comic web series of alternative love.
http://www.youtube.com/user/3dogpictures