Latour, pinned down.
Update 2019: These links seem to be dead, but the pdf of the lectures can be found here; and the videos here. The lectures are now available as a book – details here.
Bruno Latour has made the text of his Gifford lectures available as a pdf on his site –Facing Gaia: Six lectures on the political theology of nature. Thanks to Owain Jones for the link (it seems this may have been available for a while; but news to me). The lectures were all video-recorded and I linked to them a while back – the links are all at the Edinburgh site.