Early in 2009, I bought a €20 prepaid Vodafone cellphone from El Corte Ingles. I have been using it ever since. I put €5 or €10 at a time in it. Local calls/texts are around €.35/min and to the US around €1/min. Incoming calls are free and Vodafone gives out bonuses and free weekends from time to time.

I use my Magic Jack connected to the hotel wifi to call the US for free.

The best part is, as my Spanish is intermediate, I went to ECI and they have a free service where you can request a translator to help you shop. She helped explain some of the details and paperwork. She was a delightful college intern who was gaining experience for a future business career!