A little over a month ago I posted a map of the legal status of same-sex marriage throughout the U.S. It was soon made obsolete by the legalization of same-sex marriage in the state of Washington. In addition, several readers pointed out that the map hid important differences within categories.
Ned Flaherty, Project Manager of Marriage Equality USA, sent in a link to an updated and more comprehensive map at their site. Green states have fully legalized same-sex marriage; yellow states recognize domestic partnerships or civil unions; and pink states do not allow either. The lettered codes provide more information on exactly what the status is in each state:
Click on the map or go to their website to look at the much larger version; they also have a round-up of pending or possible legislation and court cases in various states.

Comments 11
Max Kingsbury — March 14, 2012
It's worth noting that although a law has been passed by the Washington house and senate, and signed by the governor, same sex marriage will not be legal until/if the inevitable for/against ballot measure is approved/rejected in November.
Anonymous — March 14, 2012
We need to stop saying 'same-sex marriage', it's marriage equality. We're not pushing for a 'different kind of marriage' it's the same thing.
Ben Zvan — March 15, 2012
Wikipedia has a great map of the world for comparison. http://en.wikipedia.org/wiki/LGBT_rights_by_country_or_territory