Calls4u

I was ready to give this site the worse review ever after using a different site that said 3 customers could make phone calls for 10p a minute only afterwards to find out that it was charging me like 35p, a penny cheaper than just phoning from my mobile without any codes.

Followed the instructions, and made a call from a 3 mobile (UK) to a mobile (Spain), and was charged 9p a minute as advertised. So in my experience it works.

Absolutely brilliant. If you have friends or family abroad and usually just call from the mobile or landline and end up with high phone bills at the end of the month, which you struggle to pay.
Calls4u has services which are way cheap, even from mobiles, just 3p/min for many countries and it works. Some of these services don't work, are blocked or just don't connect. However, the dialacode service on calls for you is fantastic, just a 5 figure code saves a huge amount on the bill each month.
If you are paying high call costs because you think that what it costs, think again. You really don't have to pay much.