Considering the Apartamentos Hispano Argentino in Madrid?
A VT member wrote the following comment about visiting Madrid:
Hire a cell phone by SirRichard
If you are gonna stay long enough here and need to use a phone all the time. Don't worry about bringing your own cell phone with you, just hire one when arriving.
Take a look at http://www.onspanishtime.com/web/index.htm