Yes there are, no problem! I myself use an Orange.es
pay-as-you-go SIM here in Spain, but I believe all the major operators offer
similar PAYG SIMs.
Furthermore, Orange offers a card to their customers
which you can buy for 5 euros in their offices and which provides foreign calls
at much cheaper than the standard rate.
Though STILL cheaper for international calls is
internet phone connections: they can be entirely free, if you are with the right
operator, once you have paid a very modest subscription to the service. This is
what I regularly use in Spain for my daily phone calls abroad.
However, if you use your own old cell phone,
which was bought for another network in another country, you may have to pay a
fee to have it liberated from your old provider's network before you can use it
on other networks: that is what I have had to do to "free" my old cell phones
from their original (British) service providers: for a relatively modest fee,
you will then be provided with a "release code", and instructions how to use
it.