Things 
                  to watch out for when purchasing a mobile phone in Spain;
                  1. Ask 
                  if it is open 'libre' or not
                  2. Make 
                  sure you get your instruction book in your own language 
                  (most dealers will give a photocopy in your language or a link to download a copy)
                  3. Ask 
                  for your guarantee card and get it stamped and dated 
                  by the dealer
                  4. If 
                  purchasing second-hand, make sure it is a digital phone 
                  and not an obsolete analogue phone and make sure you get a Spanish charger
                  5. Make 
                  sure you have the PIN numbers with the phone and make 
                  a note of them. Keep the surround from the simcard in case you ever need to stop the number
                  
                Call 
                  charges 
                  Call charge plans are quite difficult to understand, however, 
                  here are a few pointers: 
                Prepaid 
                  and contract rate plans have two groups: hourly rates 
                  and universal rates. The cost of your calls will depend 
                  on when you call. Hourly rates divide the day 
                  into several time segments each with its associated price 
                  per minute. For example, for its prepaid users, Vodafone 
                  breaks up the day into 3 segments: 0:00-6:00, 6:00-16:00 
                  and 16:00-24:00. Tariffs are much lower in the early morning 
                  and late in the day and are at their peak during business 
                  hours. Universal rates are simpler in that they offer 
                  one fixed rate regardless of the time of day, but this 
                  is on average higher. 
                
                  Call costs also depend on the destination. There are different 
                  rates depending whether you called a fixed line, to mobiles 
                  with the same company and to other mobiles. Calls to mobiles 
                  with the same operator are the cheapest while calls to 
                  mobiles outside that operator are the most expensive, 
                  so it can be worth finding out what operator your best 
                  friends use). 
                  A few other very important notes regarding calling rates, 
                  except for special promotions, all providers:
                 charge 
                  around €0.12 to establish the call, 
                  charge around €0.15 per domestic SMS, unlike other countries 
                  sending a SMS abroad is not the same price! and 
                  charge 16% IVA (18% in Jan 2011) (value-added tax) on top of their publicised 
                  rates.
                 
                If you are taking your UK mobile abroad with you, there is a cheaper alternative; You can purchase a Spanish SimCard and have it sent to your UK address. You simply use this whilst in Spain and will save a small fortune. You can save up to 90% on call charges and can purchase a pay-as-you-go SimCard or a monthly contract. 
                 
                What to do if your mobile phone is stolen in Spain here