The best way is to get a spanish SIM card as soon as you get here. The four major cell phone providers in Spain are Orange, Yoigo, Movistar, and Vodafone. There are two types of phone service contracts for sale in Spain, tarjeta (prepaid) and contrato (contract). To sign up you usually have to bring your passport or ID! Cell phones with tarjeta are prepaid and you can buy more credit at any supermarkets around town such as OpenCor, Más and Día, and Corte Inglés, at the kiosks or charge online.
For Example Orange prices are:
for 30 days 8.95€
- 1 GB Data
- 0.20 € for every call (does not matter how long)
- no fees for the SIM card
- online account to check your consumption
- presents every moth from Orange (extra GB, Extra minutes …)
You can get free Wifi in almost all the Restaurants and Bars, just ask the waiter for the password. Also there are some spots in the city where you will find free WiFi!
The Instanet company rents out modems with wifi without any minimum contract, so you can share the costs with your roommates and cancel the service when you please without any cancellation fee. Or, if you are here the whole year, you can sign a year-long contract and pay less. Plus you just plug it in, so there is no installation. For pricing and sign-up see here: http://www.welovespain.net/htmlinfo/moreinfo_internet.html