Graeme mentions that a parliamentary commission is recommending that candidates for the Senate no longer be listed alphabetically. This may not seem like much, but it's actually a huge deal.
The major parties in Spain have basically been lying about the participation of women in politics by strategically choosing women with last names that will put them later in the list than their male fellow party members.
There was an article about this last year, but I cannot remember where it was. I did find the study from 2009 that showed how this works.
By placing women on the ballot with last names nearer to the end of the alphabet (especially in regions that are contested), the parties know that only the male candidate near the top of the list are likely win. Here's an example of how it's done (notice the order of the PSOE candidates):
If you compare the number of women elected in the senate vs house, you can see how this effect has grown over the years:
The study concludes that not only are women placed against men on the basis of their last name, but that less qualified women are chosen specifically for their last names.
I suppose Zapatero wouldn't have had much luck running for senator. (Okay okay... it's Rodríguez Zapatero)