Janet
if your family have a landline then calls by you to them can be free & possibly vice versa (dependant on person having access to a computer)
www.nonoh.net.
They let you make some free calls (I think up to about an hour in total- limited to about 5 min. a call) - once you use these up then to get unlimited - no time restrictions - free calls for 4 months it costs you 10 Euros (actually 12.5 once you pay tax etc.) Once the free 120 days are up then you can start using the 10 Euros up - the credit doesn't expire.
It's not only Turkish landlines that are free - it's calls to other countries too eg. US, Singapore, Australia, lots of places in Europe etc. etc.. Turkish mobiles unfortunately are charged at 7.5p per minute.
MIGHT now be worth you lot in Turkey looking at as it seems calls between landlines in Turkey might be free using this system too. Can't be bad at 30 Euros for 12 months calls virtually worldwide - if you have a landline & computer.