I’ve used skype phone before calling SA, its about £25 a month for 90 minutes

i’ve heard of viber but could seem to get it to work on my windows phone when my mate was abroad?

Any other options worth considering?

It would be mobile to mobile to South Africa.

Mumble, ventrillo, TS3, all similar to skype etc but one may work

http://www.skype.com/en/rates/?cm_mmc=SMYT%257C1402_B1-_-Cheap-Calling-Subscriptions-The-Magic-Of-Skype/
According to skype and my basic conversion from AU$ to GBP it’s about 3p/minute to SA on the PAYG rates

I use Skype Credit all the time, put the app on your mobile (or call from the computer) buy £10 worth of credit and just dial a number landline or mobile. It works best if you are on WiFi as there is no issue with data charges. Landlines are 10% of the cost of mobiles typically, from memory a 90 min call to SA should cost you about 10p to a landline or £1 to a mobile

What they said. Skype from your own or free wifi and it is pence. I call transatlantic regularly and wouldn’t do it any other way.

Viber works well but you both have to be signed up and have good wireless/3G signals.

If your SA contact has skype on their moby as well, the call should be free.

http://www.lycamobile.co.uk/en/

Cheap easy access with pre paid card, 0800 free access from uk, and top at at supermarkets local shops etc.

http://www.telediscount.co.uk/index2.php

this is the cheapest and easier ive ever found. i was calling my girlfriend in queensland from my mothers landline for 1p a min.

for south africa its 4p to landlines or 15p to mobiles (cheaper than calling a mobile in the uk!)

Drop by your local ethnic food supermarket. Their windows are usually full of posters offering calling cards or MVNO sims with low international call rates.

+1 for Skype. I use it often to call relatives in Italy on their landlines and mobiles.

08715518585 (discount dial)works for me to SA mobiles. 8p a minute. Been using it for years, plus Skype when we want to see each other.