Cheapest way to call a landline from a mobile or a better alternative to skype

KG

I have to be away on business quite a lot and often I do not have access to a landline. (When I do have access to a landline my family call me free using the free minutes they get as part of their landline deal.)

I don't want them to have to pay to call me at all, so I set up a Skype number so they can call me using their free minutes, but the sound quality on this is poor and I spend most of the call repeating what I said.

I have a mobile and can use my free minutes to call others but I was wondering what the best option is for when these run out?

Is there a better alternative to skype to let them call me for free and, if not, what's the cheapest way for me to call them from my mobile. I am guessing there are no 'pre-dial' numbers for mobiles??

Thanks KPG