Thought this might interest other users.Dont know if its been mentioned couldnt find anything.

If you have a o2 payg sim with inclusive/bolton x-net anytime anywhere minutes, you can dial SimplyFone access numbers like
07744 97 4116, 4404, 4333 etc etc which i got from this site, and make Free Intl Calls to Numerous Intl Destinations.It only works out of cross network minutes apparently.

I saw this idea on another site,and when i registered my free sim the other day and topped up by £10 i chose the 100 inclusive x-network minute option,and the free 50 minute bolt on.

I have called Austrailia,India,and Spain for about 80 minutes , and have not been charged. I still have some minutes left and the original £10 to use as i like.So these calls are truly free.

yeh ive tried the free numbers, works nicely

cheers pal will try it out