Organisation Politique, the group that Badiou is involved with and that mainly focuses on migrant issues. I'll put aside my usual modestly and link to a couple of blog posts I wrote recently about a facet of Badiou's/OP's thought/work that troubles me:
<http://recordingsurface.blogsome.com/2009/07/25/situation-recognition/>, which expands on this <http://recordingsurface.blogsome.com/2009/07/22/economics-politics/>