Spanish residence permit - studying or investment

I am an Iranian citizen, 25 years old, and I hold a masters degree from the UK. I was wondering what options I have in order to live and work in Spain legally? With the current unemployment rate in Spain and the difficult work permit laws for non-eu people, what are my options? Is investment an option?

I was thinking maybe doing another Masters degree in Spain would give me an opportunity to stay in Spain legally for a while until I find employment. Is that realistic and feasible?