tumblr, twitter and facebook: all blue, all with crossed letters.
the other guys: at least 25% of the images contain blue. myspace, vimeo and linkedin are blue as well.
blue: the official color of social media? it’s interesting that blue is often used for tranquility, stability and sincerity. hmm…
any other blue-heavy media identities that i missed?
update: notable additions from the comments are flickr, behance, and formspring.