I have just found this on a site called justlanded.com

(The following is a cut and paste from their site)

Non-EU citizens visiting Spain need a visa (visado) in order to enter and visit Spain, unless there exists a special agreement between Spain and your home country; these countries are those of North & South America in addition to:

Andorra, Australia, Brunei, Costa Rica, Croatia, Cyprus, the Czech Republic, Estonia, Gibraltar, Grenada, Hungary, Iceland, Israel, Japan, South Korea, Latvia, Lithuania, Malaysia, Malta, Monaco, New Zealand, Norway, Poland, San Marino, Singapore, Slovakia and Switzerland.

end of cut and paste.

I cannot vouch for its accuracy or current validity - ie some of the countries are now in the EU.  But as some people ie from Australia have been posting enquiries recently about visiting Spain PERHAPS its easier than they think!

Hi there, I am Malaysian.
And I am in Spain for my 3 months (90days) visit here, and no visa is required!
FYI, I entered Spain early june 07. Before I enter Spain, I stop at Brussels for 2 days meeting.
But I have 1 new problem, which i need yr advise. My original schedule is to go back to Malaysia end of August (where the 90days stay will be ended), but due to some circumstances, I have to extend my stay here for another one month, that means I will only go back like end of September. Do you have any suggestion how can I get this 1 month extention. Some of my friends advise me to go out from Spain, for example to Germany by flight, so they will stamp my pasport, and then go to the Spain Embassy in Germany, and enter Spain again and get another 90days extension. Can this be done? Thank you so much for yr time.