Interesting post looking at some of the ambiguities behind the idea of open educational resources (OERs) including how to attribute the logo, how to create machine-readable attribution, rights filtering and academic usage. For my own part, the major weakness of OER is the raft of legalism it has created in its wake. In my world (increasingly the minority view) the default is open, licensing is something only commercial users need to worry about, and common sense prevails. An icon, for example, actually loses its usefulness if you have to attach "'OER Logo' © 2012 Jonathas Mello, used under a Creative Commons license: BY-ND" to every use of it. You may as well just use the words 'OER'. To me, the best reference is still a link to the original, perhaps behind an attribution-free legalese-free OER logo. Like this: (which, btw, is a public domain image that would make a much better OER logo).