Looking for a local number to wish your family and friends a Happy New Year's and go...online while you in Madrid?
You can easily get one prepaid SIM card from one of the big 4 mobile providers: Movistar, Vodafone, Orange and Yoigo. The two first are more expensive and usually provide better internet connexion. Orange and Yoigo are cheaper and work pretty well if you are not getting lost in the underground Madrid lol.
All the companies have stores along Gran Vía, mainly between Plaza de Callao and Plaza España. You will probably spend 15-20 euros (chip included) to get data enough for one week. I would reccomend the Delfín 16 Plan from Orange. Click the first link below to see what it includes or the second to see the map the Orange stores in Madrid. All you need to bring is a document with picture. Another tip: never, i mean never!, walk around with or passport in your pocket. You don't need to.
pd.: there is a free wireless connection at the bus from the airport to Madrid. It's "EMT"