El Mundo has covers of some of the extra editions that Spanish newspapers have published in the wake of today's horrific attacks in Madrid. And at El Pais you can download PDF's of their extra edition. And both El Mundo and El Pais appear to have suspended their usual subscription requirements, so you can see all their coverage, including their Flash graphics.

Update: The Madrid daily ABC also published an 18-page extra, which you can download here.

>Masacre en Madrid [El Mundo]
>EDICIÓN ESPECIAL DIARIO EL PAÍS [El Pais]