One thing:
I found yesterday is too interesting to wait to post. The 'free encyclopedia', Wikipedia, has a Reference page on the Madrid bombings. This is a first, I think, and shows huge promise as a future breaking news resource, if Wikipedia contributors continue to do things like this.

And later....also, Marie at Blue Ridge Blog links to Puerta del Sol Blog, which is covering the Madrid attacks and aftermath heavily. (The blog is connected to a magazine of the same name, by a British? journalist who lives in Spain, with contributors.)