Wi-Fi points in bars and cafeterias are available to customers, and most hotels offer Wi-Fi connection in common areas for their guests.
Be conscious of security when using a laptop in an outdoor location.
Mobile phones and SIM cards
Cheap mobile phones (less than €50) with some pre-paid minutes are sold at FNAC (Plaza Callao if you're staying in Madrid, or El Triangle if you're staying in Barcelona) or any phone operator's shop and can be purchased without many formalities (ID is usually required). Topping-up is then done by buying scratch cards from the small stores "Frutos Secos," supermarkets, vending points (often found in tobacco shops) or kiosks -- recharging using the Web or an ATM does not work with foreign credit cards.
The three mobile phone networks in Spain are Vodafone, Movistar and Orange.
You can hire a Mi-Fi (portable 3G Wi-Fi hotspot) from tripNETer) that allows an Internet connection from any Wi-Fi device: Smart-phones, Tablets, PCs…
"Locutorios" (Call Shops) are widely spread in bigger cities and touristy locations. In Madrid or Toledo it's very easy to find one. Making calls from "Locutorios" tend to be much cheaper, especially international calls (usually made through VoIP). They are usually a good pick for calling home. Prepaid calling cards for cheap international calls are widely available in newsagents or grocery stores around the city. Ask for a "tarjeta telefonica".